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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?

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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
up vote 17 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: They also describe methods to turn off this behavior, such as disabling hibernation altogether.

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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

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).

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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.)

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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: – 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
@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

I had the same problem except that I couldn't boot in windows 8, because after I wanted to refresh windows 8 instead of re-installing it.the refreshing stuck at "Setting up a few more things 98%". imagine this horrifying situation that you can't boot to the windows nor able to install another OS. so when Ari Pernik said "BIOS is treating Hibernation" I decided to wipe hibernate. I did this.

  1. I removed laptop battery
  2. I terned the laptop just by it's charger
  3. then when the windows installer loaded (in my case when the windows stucks at"Setting up a few more things 98%") I unplugged the laptop charger.

so after this method I could go to the Bios setting again

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protected by Diogo Sep 12 '13 at 17:19

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