What’s the difference between F5 and F8 at the boot screen?


Ian B wondered what the difference is between pressing F5 and F8 while Windows is booting.

I have no idea either. My strategy was to just mash on the function keys, space bar, DEL key, anything else I can think of. Keep pressing them all through the boot process, and maybe a boot menu will show up.

The F5 hotkey was introduced in Windows 95, where the boot sequence hotkeys were as follows:

  • ESC - Boot in text mode.
  • F5 - Boot in Safe Mode.
  • Shift+F5 - Boot to Safe Mode MS-DOS.
  • Ctrl+F5 - Boot to Safe Mode MS-DOS with drive compression disabled.
  • Alt+F5 - Boot with LOADTOP=0 for Japanese systems.
  • F6 - Boot in Safe Mode with networking.
  • F4 - Boot to previous version of MS-DOS.
  • Ctrl+F4 - Boot to previous version of MS-DOS with drive compression disabled.
  • F8 - Boot to menu.
  • Shift+F8 - Boot with step-by-step confirmation.
  • Ctrl+F8 - Boot with step-by-step confirmation with drive compression disabled.

Man, that's an insane number of boot options all buried behind obscure function keys. Boy am I glad we got rid of them. This frees up room in my brain for things like Beanie Baby trivia.

Bonus chatter: The next generation of computers boots so fast that there's no time to hit any of these hotkeys!

Comments (34)
  1. Anonymous says:

    "Boy am I glad we got rid of them."

    This seems to be a trend at Microsoft lately.

  2. computer boots too fast to press a key

    Couldn't I hold the given key down, and then turn the computer on?

  3. @Maurits: I think Windows 98 introduced holding ctrl to get to the boot menu. Mashing F8 could fill up the keyboard buffer and trigger stuck key warnings in the BIOS, but modifier keys don't have that effect.

  4. Anonymous says:

    @Maurits – not if the key is on a on-screen keyboard for a tablet-style device.

  5. And then there is F10 key for Windows (Win7+ ?) boot which allows to enter boot option string.

  6. Anonymous says:

    @Maurits: Not if your BIOS gets angry at you if you hold a key on boot (with a stuck key error).

  7. Anonymous says:

    @Maurits

    What works for me on my new Toshiba laptop is just as you said:

    I hold down the F2 key.

    Boot up the computer.

    This puts me  into the boot menu where I disable fast boot.

    Reboot.

    Immediately start tapping the  SPACEBAR (yes, the spacebar)

  8. Anonymous says:

    What I did was add a completely bogus other OS boot target. Now there's a configurable delay for the boot menu.

  9. Anonymous says:

    With Win 8:

    The initial screen,underneath icons for installed OSes, gives you an option to where you can change boot features. I forget the precise wording.  Just click on it and drill down to get to some of the familiar options.

    I'm sure that someone has written the procedure up with nice graphics.

  10. What's the difference between F5 and F8

    Confessions of a mathematician: my immediate thought was "F3, of course."

  11. Back in the Windows 95 days, I learned to press F8 in the 2-second window of opportunity to bring up the boot menu.  Simple and easy to remember.  I probably learned it in the Windows 95 getting started manual, or something like that.  (I remember there was a document aimed at existing Windows 3.1 users to help them transition.)

    After that, the situation was and is best summed up by Raymond's "My strategy was to just mash on the function keys, space bar, DEL key, anything else I can think of."  Seems like I can never get it right.  Seems like they change the shortcuts / procedure for entering the boot menu for every version of Windows since Win95.  I've found that the most reliable method is to cut power to the computer while Windows is still booting.  Then, the boot menu comes up next time.

  12. Anonymous says:

    I find myself dealing with BIOS settings much more often than with OS settings (which itself is pretty rarely).  I can never remember what key(s) I need to press to get into the BIOS settings during POST, since there's not a single standard among BIOSes.  And to top it off, the computer I do this the most with is hooked up to a TV via HDMI that has a significant delay in between a signal appearing on the cable and a picture showing on-screen that I don't have the opportunity to read the BIOS's instructions on what buttons to press to reach the settings.

    So I end up like Raymond: rebooting several times while mashing various keys until I get it right.

  13. Anonymous says:

    I usually just tapped F8 until it brought up the menu.  That was easy enough to remember.

    When dealing with BIOS settings, I usually just keep repeating the sequence of Delete, F2, F1.  It seems to work on quite a few machines.

  14. @Maurits

    > What's the difference between F5 and F8

    Confessions of a mathematician: my immediate thought was "F3, of course."

    Wrong! 0xF5 – 0xF8 = 0x02 in 8-bit arithmetic.

    Or…. 0xF8 – 0xF5 = 0x03

  15. Anonymous says:

    @Brian EE: Close, but I get x'FD', or -3 in the former case.

    In any reasonable interpretation the Fs cancel out in the subtraction.

  16. Anonymous says:

    @Ray

    Very nice link about the entire W8 booting experience and how they changed the way you reach the boot menu. I like it. However, one thing bothers me – what will happen when failproof system that will load the menu at OS start-up will fail to detect that W8 while loaded is unusable and will not show you the menu? Ain't that situation the killer and users will get back to mashing F8 in a frenzy? I do hope they still left F8 there, even if it has a <100 ms window time opportunity. Because in the lab world of MS everything is nice and white while we live in a world with hardware made cheap on Taiwanese ships and running drivers coded by some drunk developer on his bad day.

    [I don't know but here's an idea: If you get into this state, then power-off the machine while it is booting. That will presumably trigger the failsafe at next power-on. -Raymond]
  17. Anonymous says:

    @Brian EE and Mr. Cranky

    He said "difference", not subtract F8 from F5. And here it goes: F5 to F6 – 1st difference; F6 to F7 – 2nd difference; F7 to F8 3rd difference – 3 steps, hence F3 as his answer. I totally agree. And same goes down from F8 to F5, still 3 steps, do I need to write them as well?

  18. Anonymous says:

    F5 and F8 were already in DOS 6. F5 skipped all of config.sys and autoexec.bat, and F8 asked for a confirmation for each line.

  19. Anonymous says:

    Hint: Watch for the keyboard lights (caps lock, num lock, etc) to flash, then press your key.  

    The lights flashing are the keyboard reset, after which the keyboard reads begin.

  20. Anonymous says:

    computer boots too fast to press a key

    Will they beat old home computers like a C64? :)

    On topic: I always used F8, the other options I needed were then easily available from there.

  21. Anonymous says:

    Another way to compute the difference between (0x) F5 and F8 is to compare the bit patterns. They differ in bits 0, 2 and 3, so the difference is 0x0D (i.e. F5 ^ F8).

    Versions of DOS differed as to what F8 would actually step through; some of them would only let you step through CONFIG.SYS but others would let you step through AUTOEXEC.BAT as well.

  22. Anonymous says:

    That is more than I had imagined O_O. Thanks for responding!

  23. Anonymous says:

    @JMThomas, I don't have keyboard lights, except for "low battery".  It's wireless.

  24. Anonymous says:

    This was great. When I read the title my first reaction was, "Does it matter you are going to mash them all anyway!"

  25. @Danny, @Neil,

    @Maurits said "Confessions of a mathematician…"

    In mathematics, "difference" == "subtraction". Bitwise differences occur are a representation of computer science, and do not exist in pure mathematics.

    And the original question was in regards to "functional difference", not positional difference.

  26. Anonymous says:

    [I don't know but here's an idea: If you get into this state, then power-off the machine while it is booting. That will presumably trigger the failsafe at next power-on. -Raymond]

    Sigh. Hold Ctrl while booting (from Win 98) was the best way. Have we fallen so far.

    [You're assuming that the computer has a keyboard with a Ctrl key… -Raymond]
  27. Anonymous says:

    A.

    Absolute difference != difference.

    B.

    Why use Beanie Baby when you can play with a *smart* ActiMate?

    C.

    Windows8 "boot" = resume from hibernate.

    Windows8 "reboot" = hibernate+resume from hibernate.

  28. Anonymous says:

    @640K

    Are you saying that W8 is always saving it's state to hibernate when is shutting down? Where did you read that?

  29. Anonymous says:

    [You're assuming that the computer has a keyboard with a Ctrl key… -Raymond]

    No, I'm assuming working USB ports. It's not like the boot menu's going to work without a keyboard anyway.

    [The Windows 8 boot menu doesn't require a keyboard. -Raymond]
  30. Anonymous says:

    [I don't know but here's an idea: If you get into this state, then power-off the machine while it is booting. That will presumably trigger the failsafe at next power-on. -Raymond]

    Sometimes it does, sometimes it doesn't. It also doesn't help that Windows is not giving any feedback as to what it's doing after you select anything in the failsafe menu (which only gives you the options of Restore and Cancel the first time you get to it, and you only get the other options later – if at all) – after selecting any of the options, you're left with the blue logo on the screen for 5-10 minutes, and no indication that anything is happening until the machine suddenly reboots.

    What is it with Windows 8 and hiding information anyway? My machine was giving me some trouble (no video after the bootup logo vanished), and just getting into the failsafe menu was a pain (had to hard reset several times during bootup to get it to appear – and when it appears, why doesn't it offer boot to Safe mode immediately anymore?). I really liked (not!) the "Windows is checking your hard drive. This might take over an hour" it showed a few times. If the process might take "over an hour", why's there no indication of progress (luckily it took only a minute for me, but that's because I have an SSD). Is there a policy I could set to get more verbose messages in these cases?

    [The Windows 8 boot menu doesn't require a keyboard. -Raymond]

    Yeah, and it's keyboard usability is pretty bad compared to the old one. (and I still don't see why supporting holding Ctrl to get the boot menu to show in addition to what it currently does would be a problem)

  31. Anonymous says:

    If the device doesn't have a keyboard then make holding a finger on the bottom left corner of the screen do the same thing.

  32. Anonymous says:

    @Dylan: good idea – my Garmin GPS does something very similar.

  33. Anonymous says:

    @ender: maybe your computer switched to an alternate connected display…? Mine prefers the HDMI-connected flatscreen to the display on the DVI port.

  34. Anonymous says:

    @NoP: I've got NVidia GTX470 with two displays connected (one DVI, one DisplayPort; boot display is DVI). Both went to sleep after logo disappeared.

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