Help! Can’t unlock my Windows Phone 7, can’t deploy my XAP file, or can’t run my app!

Don't panic! Usually these issues are very easy to fix: 

1-Zune software isn't installed or wrong version:

Usually if this is the case, when you plug your phone's USB cable, Windows won't recognize it. Check if your Zune software is 04.07.1404.00 or above that.

2-Zune software detects the phone but it says it can't connect to it:

Look at windows device manager. If you find an "unknown device", right-click on it and try updating the driver. If this relates to Windows Phone 7, the driver can be found online and will be automatically downloaded.

3-Zune software detects my phone but I can't deploy my XAP from Visual Studio:

Remember you first need to register it using the "Windows Phone Developer Registration tool" (Start menu/Windows Phone Developer Tools).

4-Trying to use the Windows Phone Developer Registration Tool but doesn't connect to my Windows Phone 7:

Again, check the items 1 and 2. You need the right version of the Zune software and the USB driver must be right. Also remember the phone must be on and unlocked (the screen must not be asking for the password or off).

5-Windows Phone Developer Registration tool detects my phone but doesn't proceed after I put my Live ID information:

Likely scenario is that your Live ID isn't configured as a developer on

Also check if there isn't a firewall blocking your internet access.

6-Visual Studio says I've reached an application limit and can't deploy my app:

There is a limit for how many apps you can sideload as a developer to a single device. If you reach this limit, just uninstall one of these apps from your phone and try again.

7-I don't have the source code, just the XAP and I need to sideload on my testing windows phone 7. How can I do it?

If you did install and configure everything as mentioned in the previous items, you can use the "Application Deployment" tool on Start Menu/Windows Phone  Development Tools.

8-My application runs fine on the emulator but when I run it on the device, it shuts down suddenly without any warnings. Why's that happening?

The most likely scenario is memory. Keep in mind the OS will shut down your app if it doesn't handle memory very well. Monitor when debugging and check the RAM usage. See if you are freeing up memory accordingly. Second most likely scenario is a .Net Exception not being handled. Try debugging it.

9-My application can't play any mp3 files. When I try it, it just fails:

Disconnect your phone from Zune. If it is connected, it won't play. Also check if the audio file is DRMed.

10-When my application uses the XNA library's media player to play a background music, it just quits unexpectedly:

If you build a Silverlight app and try to use XNA to play an audio file, you have to consider a few things. First, you'll have to deal with XNA's FrameworkDispatcher.Update method, like mentioned in this article:

Second, there are differences between DRMed and non DRMed songs. As a guideline, always call your play method within a try catch block and show a message to the user if you can't play the song explaining what is going on. Your application probably won't pass the certification if you don't do that!

Hope that helps 🙂


Comments (23)

  1. Ronald Wells says:

    Thank you so much.  I have been trying to launch on my device for hours and visited many forums.  The start menu/dev tools location was all I needed.  If they only included that when they shipped the dev phones.  Thanks again.  The new phones are awesome by the way!!

  2. Sergii says:


    I registered as a student at but when I try to unlock my WP7 for development I've got an error: Marketplace registration incomplete. Please return to the developer portal for more information. (ErrorCode:0x80043009)

    I shuted down my firewall, but it wasn't help.

    What is the problem?

    Best regards,


  3. Hi, when you look at your account at create.msdn, what is the current status? Did you pass the geotrust verification already?

  4. Gerhard says:

    Hi I'm also a student and have the same problem here.

    Do I have to upload a first application to be verified? I've heard something like this …

    That would make not much sense, because a test on real hardware would be interresting before uploading 😉

    Does anyone know something on this matter?

  5. Guys, could you please send me your Live IDs (to my e-mail: so I can chase this up and see what is going on with your cases?



  6. Eric Sylvestre says:

    I'm also in this situation.

    I can't understand how a I could submit an app that has been not tested on a real device.

  7. Joopa says:

    Developer Phone Registration tool is not only uninformative with it's cryptic error messages but also buggy.

    I did the AppHub registration but now when I try to do the Phone Registration it get's stuck in first screen saying 'Unable to connect to Phone'. Zune fires up normally when I plug the phone to USB and I can see phone content in Zune.

    I can't tell how much I've started to hate this registration mess. Nice phone but in it's current form it's crippled with incredible buggy registration process and tools.

  8. Jeff Law says:

    A very helpful list of potential issues but it still doesn't help!

    What port(s) should be open in the firewall?


  9. I don't think it requires any special ports other than http/https. Sometimes you just have to try again to make it work. If problem persists, drop me an e-mail with your details (including your live ID) and I can open a support request.

  10. Kyzer says:


    Do students need to submit an application to the marketplace in order to register their WP7 as a Developer Phone?

    Best regards,


  11. Thanks Mat!  The Windows Phone App Hub really should make it more obvious how to unlock a developer phone.  I couldn't find it anywhere on that site, so thanks for pointing me to the installed developer tools.

  12. Kyzer, depending on how your acct has been migrated, it may be necessary to publish a first XAP to get the account registered.

  13. Marko says:

    Hi Mat,

    I got a App Hub developer account through DreamSpark (student). I am getting the code above (ErrorCode:0x80043009) when I try to register a phone. Can you help ?

  14. Yes I can help but I need you to send me an e-mail. My e-mail is above.

  15. Miguel says:

    I've got the strange "Error communicating with the developer portal. Please set the correct date and time on the phone, check Internet connection and try again later (ErrorCode0x64)"

    I've checked everything (date and time, internet connection)…

    but nothing

  16. Again, I can only help you if I know your e-mails. If you send me one I can try to help. Also, Miguel, this issue sometimes is fixed by just retrying a few times, happened with me too.

  17. Edvin says:

    I also have the Errorcode: 0x80043009 when I try to make a developer Phone registration, should I send you an e-mail?

  18. a2z says:

    Hi MV, I am also unable to register my phone. I have created and acount on appshub and verified it using dreamspark. Now im trying to register it using Windows phone registration tool but im getting error message which reads "Error Communicating with developer portal. Please set the correct date and time on phone, check the internet connection and try again later(Error code:0x64)".

    My phone is connecting with PC perfectly and sybching as well.

  19. Federico says:

    Hi, Matteus

    I have an HTC Mozart Device, i suppose that my Windows Live ID is correctly registered on Developer Portal.

    My device connect correctly to Zune, but Windows Phone Registration Tool display thaw was unable to connect to windows phone.

    Thanks for any support.

  20. joe says:

    I dont want to upload a .XAP, even if its an empty one, just to be able to register my phone for testing..

    Please correct kind sir.

    Thank you

  21. Subir says:

    Hi…is there any possibility of free registration where-in i can use the tools just install .XAP file in my HTC Mozart…just for a start as i am very new to this world……thanx…

  22. vlcrpt[0]r says:

    I don't know if its that I had to upload things to run apps on my WP7, but I never had an issue. I'm a student, but I got my developer license not through DreamSpark, but through a promotion in Australia where students could get full dev accounts for free… I released 4 apps before Microsoft gave me a device, so they were all tested purely on the emulator. Since getting my Lumia 800, I've been testing the game I'm currently working on  on it and have encountered no problems and am nothing but thankful to Microsoft for the opportunity and the free software and hardware… Hoping you guys manage to sort it out :S

  23. paul mcduffie says:

    I just got my windows phone based k from my wife and I’m locked out and she doesn’t remember the code she used so I’m locked out of the phone . How do I open it?

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