Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Today I installed Windows 8 Consumer Preview on one of my notebook machines and I noticed that I can't access BIOS settings if I use the "Shut down" Windows option on Settings/Power menu. If I use the "Restart" option, my BIOS allow me to enter on it's settings over "F2" again.

Is this happening to someone else? I looked over Windows 8 oficial forum and couldn't find such event. Is this something foreseeable to the new Windows 8?

share|improve this question
    
Do you actually see the BIOS screens in both cases? Are you using a wireless or backlit keyboard in lieu of the internal one? –  Shinrai Mar 1 '12 at 18:43
    
Yes, I can see the bios screen on both cases, but just on "restart" situation the F2 Bios option is displayed and allowed to enter on bios settings... It is a notebook integrated keyboard. –  Diogo Mar 1 '12 at 18:50
    
@DiogoRocha What hardware are you experiencing this on, Make and Model if you don't mind. –  Moab Mar 2 '12 at 0:05
add comment

3 Answers 3

up vote 16 down vote accepted

This is an artifact of your BIOS is treating Hibernation (S4) Boot and Normal Boot (S5) differently in regards with access to the BIOS menus. The default in Windows 8 for shutdown is a Hybrid Boot (which appears to the firmware as a Hibernation), described at length here: http://blogs.msdn.com/b/b8/archive/2011/09/08/delivering-fast-boot-times-in-windows-8.aspx. They also describe methods to turn off this behavior, such as disabling hibernation altogether.

share|improve this answer
1  
THAT would explain it! –  Shinrai Mar 1 '12 at 19:18
    
+1, completelly explained for me. Thanks –  Diogo Mar 1 '12 at 19:45
    
So, Windows 8 will restrict us to access BIOS options just when "Restart" power option? I mean, it will always happend from now on? –  Diogo Mar 1 '12 at 19:48
    
Other firmware implementation don't have that problem. :) –  Ari Pernick Mar 1 '12 at 20:20
    
@DiogoRocha - On this particular motherboard, if you don't disable this behavior, the answer appears to be yes. (Most motherboards SHOULD disable this because changing settings before resuming a hiberfile could actually cause severe problems. A lot of them DON'T disable this, though). –  Shinrai Mar 1 '12 at 20:20
show 1 more comment

Shortcut for anyone wishing to do a full shutdown in windows 8 (which will allow you to access the BIOS when powering on afterward). In a command prompt, run:

shutdown /s /t 0

...or just choose the restart option instead (which will do a full shutdown first).

share|improve this answer
add comment

There's different types of restart. A warm restart can skip the bios option and a cold restart (the power button) will always go thru the bios. Apparently whatever software restart option you are using is only doing a warm restart. Try powering off and restarting cold. (I believe this can happens with other OS's too.)

share|improve this answer
3  
I think you've got this backwards. I'm reading the question as a warm restart DOES allow BIOS access and a cold restart DOESN'T. –  Shinrai Mar 1 '12 at 18:43
    
This page from microsoft mentions that a cold boot does a post, a warm skips it: support.microsoft.com/kb/102228 –  jdh Mar 1 '12 at 18:54
    
Is a Post test related to the allowing or disalloing of entering on BIOS options(F2) or boot selection(F12)?? –  Diogo Mar 1 '12 at 18:57
    
@DiogoRocha - Sometimes, yes. This really depends on the motherboard. If anything, though, I'd agree with this answer and expect your situation to be BACKWARDS. Win8 has some different restart methods but you should ALWAYS be able to access the BIOS from a cold startup, and you're saying you can't (right?). If you can't get into it from a cold start that should have nothing to do with Windows, you should be able to yank the hard drive out and have the same problem, so it's a bit puzzling to me. –  Shinrai Mar 1 '12 at 19:10
1  
@Shinrai - Yes, I see what you mean in the question, its the reverse of what you would expect. Maybe the software option to power off is doing some type of hibernate, not really powering off? –  jdh Mar 1 '12 at 19:14
show 1 more comment

protected by Diogo Sep 12 '13 at 17:19

Thank you for your interest in this question. Because it has attracted low-quality answers, posting an answer now requires 10 reputation on this site.

Would you like to answer one of these unanswered questions instead?

Not the answer you're looking for? Browse other questions tagged or ask your own question.