Fix: Windows 10 upgrade couldn’t update the system reserved partition

Disclaimer: This is what worked for me, and it’s not guidance from Microsoft. It may not work for you. Since this involves resizing partitions, it could wipe out all of your data. You may want to create a backup first. Proceed at your own risk.

Over the weekend I upgraded my machines at home to Windows 10. I had two desktops and one Surface Pro (the first one) running Windows 8.1. Since I had multiple machines to upgrade, I downloaded the Windows 10 installer to a USB flash drive using the media creation tool mentioned on Download Windows 10. For me, the media creation tool wouldn’t recognize the USB drive, so I chose the ISO and copied the contents to my flash drive. I used the flash drive to upgrade my Surface Pro with no issues.

Then I tried to upgrade my desktops. The first one failed with the message saying, “We couldn’t update the system reserved partition.” That happened after it downloaded updates (that takes a while). I tried my other desktop and got the same message.

I pulled up diskmgmt.msc and saw that my system partition had a size of 100 MB and was essentially completely full – 3% free. Both machines were in that state. So I started searching for a solution. I ran across a couple of places, such as this one on reddit, that had a set of instructions to free up space. It included commands that I didn’t actually know existed (I’ve never needed takeown).

I followed the instructions and had more than 50 MB free on system partition. I ran the Windows 10 upgrade, and this time it got further before failing and failed with a different message (I don’t remember exactly what it said).

At this point I decided to extend the system partition. The thread on reddit mentioned a tool called MiniTool Partition Wizard Free. I did a search and found a review on PCMag. They were complimentary of the pro version, so I decided to give it a try.

The UI makes it really easy to drag the OS partition to resize it a bit smaller and then extend the system reserved partition to make it bigger. I shrunk my OS partition by 200 MB and increased the system reserved partition to 300 MB. After hitting Apply, Windows has to be rebooted for the tool to make the change. I did that and let it do its work, and then all was good. Windows 8.1 booted up just fine with the newly resized partitions.

I ran the Windows 10 upgrade again, and the upgrade proceeded smoothly. Thanks to the folks at MiniTool for a great tool!

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Comments (72)
  1. ade says:

    Thanks for the info, I have been able to resolve the issue I had with installing windows 10.

  2. mark says:

    Thanks much. I had the same issue and your post helped me resolved the issue.

  3. RAV says:

    This description is very informative. I wish that Microsoft do this for all of us, or even better – create the script to do it for everyone during the update. Did Microsoft have no knowledge about 100MB partition in every Windows 7 system? This is how they test an upgrade from Win7 to Win10? Some may say…be happy to get it for free. Maybe. How many people will not upgrade to Win10 because of this issue?

  4. Mike says:

    For anyone with the system reserve partition issue, this is the way to fix it. Ive never done any partition resizing, but after watching a tutorial on the miniTool partition website it was so easy. And after resizing my system reserve partition from 27mb to 350mb with the tool, windows 10 installed with no issues. Thanks for the article sir, worked perfect.

  5. matt says:

    Can't get windows 10 on my brand new laptop  I have tried everything for the past 2 weeks  I spend countless hour every day but still nothing you dumb idiots forget microsoft I hate you

  6. Graham says:

    I have the same problem when upgrading my Windows 7 to Windows 10. My solution is similar but with another free partition software named AOMEI Partition Assistant Standard. Very easy.…/resize-partition-windows-10-0528.html

  7. Chris Palmer Sr says:

    The miniTool partition wizard Free tool worked flawlessly. thank you. .c.

    1. Russell K Acton says:

      It did not work for me.

  8. OnlyInYourHead says:

    This tool worked.. I extended my partition.  Thank You.

  9. Dale says:

    Here is my update to the Couldn't Update System Reserved Partition for Window 7.

    Here is the Link I used to get it to work.…/9154c2b1-b807-439d-8873-9699415eb657

    Install this program…/epm-free.html  

    These are the Steps for me to get this done. I was successful in upgrading to Windows 10.

    Open EaseUP Partition Master, Right Click on your Main Partition C: on the bottom part of the page.

    Click on the Resize / Move Partition Button.  In the New page clink into the cell of Unallocated Space Before, Input  400mb, Click OK. Know you will be on the main page. At the bottom part of the page if the Unallocated partition is on the far right drag the C larger partition to the right (Right Click an hold the right and drag it to the right and the Unallocated partition will move next to the Data Partition. You will need to make sure the unallocated partition is to the right of the Data Partition or is will not work. Click on the Data partition on the bottom part of the page to highlight it. Click on Resize / Move partition button. In the new page drag the Right Bar little circle and pull it to the right to give you 500mg. Click OK. Back to the main page you will see Data Partition moved to 500mg. Click Apply, Click yes to the next two pages and it will reboot your computer. This will take a while to reallocated the partitions. To check if it worked go to the Start Button, Control Panel, View by Small Icons (Upper Right), Administrative Tools, Computer Management, Double Click on Disk Management.  You will see if you increased the Data Size

  10. TwoMetreBill says:

    Why can't Microsoft fix this problem? We shouldn't have to jump through hoops to install the next version of their OS. I've installed every OS that they've ever built from the days of DOS Version 1; why can't they build an install that works for their latest and greatest OS?

    1. Chris says:

      Absolutely! They are so disrespectful of their customers time…Microsoft needs to sort this out – I’ve wasted hours on this and ended up having to reinstall Windows on the SSD – and pay someone else who has specialist leads for the action as I was locked out. I’m in the top 10% of IT ability yet had problems so this is very unfair for ordinary customers. Surely there are enough people in Microsoft Corporation to ensure this nonsense doesn’t happen – I’ve run IT companies and wouldn’t dream of allowing a release like this. Unimpressed!

  11. Les Ordway says:

    I had the same "Reserve Partition" error on my factory configured Dell Latitude E6430s when trying to upgrade to WIN 10.  I too used a tool to resize the master partition to get the upgrade to work.  I just don't understand why Microsoft doesn't have its installer take care of this for us.  At a minimum  they could have provided instructions that the average person could follow to resolve the problem.  There must be some ulterior motive, probably something that provides them a  greater profit.   Possibly if you pay for the upgrade down the road the installer will then do the job for you.  Its either that or they simply are doing a poor job with the WIN 10 roll-out.  What do you think?

  12. Jeff Barnes says:

    This seems to work for me.  Thanks a bunch.

  13. Win says:

    This is an excellent solution.  Far simpler than other solutions that have been posted regarding this problem.  Just a note about the free MiniTool Partition program, which is quite good.  Once you Move/Resize the partition where you are going to recover some space from, when you go to the Data partition, be sure to use the Expand command, as the original author notes.  The Move/Resize command won't work to increase the size of the Data .system partition.  You have to Expand it.  My Win 10 upgrade was a breeze after I solved the problem of the system partition being too small.  

    1. Eric Carter says:

      I don’t see any expand operation. Do you mean extend instead?

  14. Jeremy says:

    I have expanded the partition size, and it is still not working. I have moved the partition to another location and redirected the boot location and I still get a system reserved error.

  15. Patrick says:

    This product worked extremely well !!!

    Be sure to use the 'Expand' Option instead of the 'Move/Resize' Option like Win says above.

    He is right !!!

    The 'Expand' Option is much easier because it combines the resizing of both partitions into one easy and intuitive step.

    I was very pleased with the results !!!!


    And yes – I will most likely purchase a copy !!!!

    1. DocR says:

      “Extend”…not expand….

      1. Mike Adams says:

        Thank you for this!! And thanks Doc R. – I was going nuts trying to find “Expand”… (it’s EXTEND)

  16. Stevie says:

    I tried to follow Dales instructions and now nothings opening or working on my computer Ive obviously done something wrong how do I set the partitions back to how they should be ???? Someone please help!!

  17. Peter says:

    I've got the same problem, and have to steel myself to deal with it……..

    Isn't it time we found somebody to satirise Microsoft in general, and Windows in particular?  The steps of the White House would be a good venue, I think…….

  18. Booga says:

    This worked like a charm. I had 100MB and 62% used. Used the miniTool to to Extend the partition and in 1 click and a reboot, the updates installed. Thank you very much.

    Oh, and I had had 2 Answer Tech try to fix the problem to no avail.

    P.S. On Windows 10

  19. Ger says:

    Thank you! I had the same problem and your fix worked perfectly for me.

  20. thanks says:

    It is stuff like this that makes me wish M$ would fail as a company.   The error should say "We are sorry, after months of taunting you to upgrade your PC to the new improved Windows 10, we realized that we did no checks before hand to let you know that your PC is inadequate and cannot be updated….  Unless we actually did some research ourselves and realized that almost every PC out there will fail because the system partition that *we* created not long ago is insufficiently small.  Now we can fix this if we really wanted to and not even bother you about it but we decided that we would just abort with no explanation because we are just real idiots and know that you will figure out how to do our job for us.  Thank you.  Please let us know when you have fixed your broken installation of Windows so we can continue to bring you the next best Windows version ever conceived!"

  21. Michael Markowski says:

    Many thanks for this post, it worked great for me.  In my case, the 100MB System Reserved Partition on my Samsung 840 EVO SSD was put there by the Samsung Magician software, not Microsoft.  It was 99.8% full and had long prevented me from upgrading to Windows 10 (from Windows 8.1 64-bit).

    After finding this post, I backed up the entire OS drive using Macrium Reflect Free and then launched MiniTool Partition Wizard (MPW).  In MPW, I never did anything with the OS (C: drive) partition; all I did was select the System Reserved Partition and click "Extend".  When I used the slider to increase the partition size from 100MB to 1.2GB, the size of the OS partition automatically adjusted down by the same amount.  I clicked "Apply" and MPW rebooted to do its work in pre-OS mode.  Sure enough, when it was done I had a 1.2GB System Reserved Partition and no problem installing Windows 10.  I made the system reserved partition 1.2GB because, frankly, I never want to be faced with this problem again.

    Thanks again.

  22. Norm Lope says:

    Thank you so much. It worked.

  23. Vahn says:

    Using the extend option is definitely the way to go. I've installed Windows 10 on 17 different laptops and had no problems, but the 18th had this system reserved issue. Glad this guide was here. It's worth noting that you will only have this issue if the system reserved partition is full past a certain point and there isn't enough space remaining. For most users it isn't a problem. Even if Microsoft increases the reserve partition size, people who have computing habits that occupy the system reserved space will still fill up the space and have this problem.

    Programming is hard work, you have to try and prepare for every eventuality. The fact that we got error messages instead of it doing a bad install and ruining the OS on the machine means that they did their jobs. Let's be glad there is such a simple solution to this problem.

    1. Jim says:

      I have a large system partition on an SSD laptop. Don’t know what I’m doing that might “clog” it, but how do I find out what’s clogging it so it can be deleted?

  24. Vivek says:

    Worked for me. Thanks.

  25. Kopiraj says:

    Really very very useful tips. thank you so much for sharing…!!

    Thanks a lot..

  26. blueglacier says:

    i have a lenovo t430 and i cant download win 10 it stalled at 32 % for 6 hours

  27. Marcel Katz says:

    PERFECT!!! Perfect solution. Thank you! Downloaded the “Mini Tool Partition Wizard Free”, re-sized the “Data” partition from 100 MB to approx. 450MB, rebooted the machine, and re-launched the Windows 10 Installer successfully.

    1. Marcel Katz says:

      Also, in “Mini Tool Partition Wizard Free”, make sure to use the “Extend” option to re-size the partition, and then click “Apply”, before re-booting.

  28. Geoff says:

    I don’t have a system reserved partition. I have two Recovery Partitions. One is 489MB, other is 2GB. Both partitions are 100% free space.
    So, no idea what’s happening on my end but it doesn’t look like lack of space.

  29. Alex says:

    I had Win10 Pro installed already and got this error on an upgrade.
    The solution is the same. :)


    1. joe says:

      Worked great; thanks!

  30. Warfi says:

    I have applied these steps and many others too but none of these are working and Windows 10 is not getting installed. Still searching for the solution.

  31. Ever says:

    Excellent solution, better then MS site. Thank you !!!

  32. karen dixon says:

    My tool bar at the bottom of the screen doesn’t work at all. what can i do to fix it.

  33. JP White says:

    Thanks for the tip on MiniTool Partition tool.

    It is quite unique in allowing partitions to be moved in either direction into unallocated space. Most partition tools are limited to extending partitions and can’t change the start point. Very handy!!

    Solved the WIN10 upgrade issue :-).

  34. Phixxer says:

    Bloody good piece. Worked like a charm. Thanks much

  35. Duplex says:

    Excellent post – helped me resolve my issue. Thanks!!

  36. zachary says:

    worst where window 10 start sudden become freeze worst find window update download
    sense maybe window update no long stop work cut download restart return window update strange wait too long hour
    not open nothing return wrong with this problem don’t know where fix not see hide bug much problem can’t fix maybe lost or destory window10 shut down forever frustrate me.
    overwhelm please don’t too much list many fix hide bug in much mess up problem not sure window update or not sure window 10. maybe destory window 10 . me can’t fix waste. up give me overwhelm .thank you

  37. Alex says:

    Just an FYI to those. This may or may not cause an issue with your boot/mbr, and you might get a start up error.. Just do a start up repair from your windows 7 image and it will fix the issue.

    Also the newer version of MTPWF, you must right click your system drive and click EXPAND.

    Good luck!

  38. Gene says:

    Just ran into that error and the command line fix made my eyes blur. I do not want “get one comma or space wrong and it all melts down”.
    Your idea to use MiniTool worked as advertised and I was able to move on to the 10586 Windows 10 upgrade. (Of course I did make a full backup before proceeding).

    You saved someone’s sanity, Buck. A big Thanks!

  39. pjc says:

    Minitool fixed this issue for me as well, with a very simple extend, well sort of. It not only fixed the the Win 10 upgrade problem, but it also fixed the issue where there was not enough space on the data partition to do image backups. That started happening after running the Samsung SSD migration tool. I guess it filled up the data partition. (I was using Clonezilla instead as a replacement). Apparently Windows backups use the data partition for some reason as part of its backup routine.. However, minitool did destroy the boot up files, so I had to do a system repair using the Windows install CD. After that it booted just fine. I always wait at least 6 months to do an OS upgrade; waiting for the main bugs to be squashed, or making sure Microsoft doesn’t release another nightmare like Vista or Windows 8, so I can skip it.

  40. greg says:

    Thanks! Saved me much time

  41. Mario says:

    Thanks for this gem, it totally worked for me.

  42. Trips says:

    THANK YOU!!! I had a feeling this was the problem. This confirmed my suspicions. However, the free tool you suggested was easy to use and I appreciate you posting the link!
    Thanks again. Win10 is installing as we speak!

  43. Ricardo Elsewhere says:

    You are my new best friend. I literally had my USP in my drive with a clean Win 10 install ready to activate when I Googled one last time for a solution that would not require reloading the OS. Your suggestion, and software recommendation, worked splendidly.

  44. Nils says:

    Thank you for this post, it saved me a lot of time! The partition wizard tool did the trick.

    First, I read the knowledge base article from Microsoft about the “takedown” command, but this way of resizing was SO much easier, and solved my problem in a jiffy. I had a 100MB system reserved partition, that only had about 8MB free space, set it to 500MB, followed instructions of reboot and let it do its thing, and afterwards Win10 installation proceeded as intended.

  45. my computer would not install this program partition wizzard

  46. my computer windows 10 would not install partition wizzard.

  47. Paran says:

    Thanks for the info. The MiniTool Worked great was very easy to use and resolved my system partition space issue during windows 10 Upgrade.

  48. Louie Arada says:

    I need to know how to resolved my windows 10 could not be updated due to reserved partition..//???

  49. PeterH says:

    Thanks for this post ! I was close to pulling my hair out, when I read your solution, tried it, and my pc is now running anniversary update 1607 ( updating from W10 1511 NOT from W7) ‘happily’. One scary moment when Free MiniTool Partition Wizard told me I had to introduce the recovery or original OS disks (W10 OEM installed – no disks..), but hitting OK again rebooted my pc, the update downloaded, installed and runs well ! Thanks again !

  50. Cees says:

    Little bit scary to “play” with partitions but this solution works. Thanks a lot for your post!

  51. S Schwam says:

    Microsoft should maybe check the reserved partition and correct it before doing the upgrade. I think many are having this problem.
    Microsoft wants people to have the anniversary edition of Windows 10 does it not?

  52. Dave says:

    I’m having this issue going from 1607 to Insider Preview. Has anyone come across this error when the system and recovery partitions are empty? My HP laptop has a 450 MB Recovery Partition, and a 100 MB EFI System Partition. Both show 100% Free.

  53. kazuma says:

    mine is showing 100% free yet i am unable to install the creators update

    1. Osama Idrees says:

      I am also having the same issue, the system partition shows 100% free yet I am having the same error.

  54. Mohana Krishnan says:

    Thank you very much. Really it worked.

  55. Many thanks Buck, this worked perfectly with the MiniTool Partition Wizard Free.

  56. rick fulton says:

    the solution does not appear to work with mini-tool if your on win 10 1703 and upgrade to 1709. Here is an alternative

  57. Richard Wilbur says:

    I just bought the tool you mentioned and it was a waste of time and money. It will not allow me the choice to change my Reserved Partition and yes I bought the Pro Edition.

  58. John says:

    Old article, but worked with a laptop that wouldn’t install Windows 10 January 2018 update. Software worked great to expand the partition and then upgrade went flawlessly, Thanks!

  59. David George King says:

    I am unable to even find my System Reserved Partition – I have 5 partitions on the SSD one of which is unallocated – when I ran the AOMEI partition wizard I got 10 partitions showing – none named SRP 6 of them are System Volume 1 ESP (EFI bootsect.Boo) and 2 boot partitions which I can’t fully identify – I reckon Windows 10 has shredded my SSD – Microsoft level 2 technical support has been assisting but the issues are seemingly beyond them.

  60. Dericslab says:

    I personally had an issue with the MiniTool Partition tool, and I then found a solution on the Microsoft Support site. (I admit usually their support is not always helpful). This method took me 20 seconds, and it worked. I highly suggest this method first:

  61. Russell K Acton says:

    I tried a mini tool partition and extend it and was told to restart and it took me hours to get back into windows

  62. rkacton says:

    It didn’t work for me. I used that minitool and it said to restart and it took me hours to get back into windows

  63. Piter101 says:

    There are 2 reasons that can lead to the issue, they are
    1: system reserved partition is full. Microsoft says some third-party anti-virus and security apps write to the system reserved partition, which could fill the partition up.
    2: File system of system reserved partition runs in error.

    I have read one post by MiniTool titled – Best Fix: “We Couldn’t Update System Reserved Partition” Windows 10
    You can just solve the problem with its power and reliable software – MiniTool Partition Wizard.

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