Locked myself out of Windows (By accident, oops!)

So I wanted to set up a dual-boot between Windows 8.1 (With update 1) and Ubuntu for Android development on my Acer Aspire V5-571P-6429, rather than using a Vitual Machine and having to share resources. I went and modified my UEFI settings and changed it from UEFI to Legacy BIOS to disable secure boot, then applied the changes and away I went... Or so I thought. I got the PCIE boot screen, and if I cancel it, or if it fails (Which always happens), it goes on to say the OS was not found. I've seen various solutions, like here:

http://community.acer.com/t5/Notebooks-Netbooks/Aspire-V5-571-quot-Operating-System-Not-Found-quot/m-p/37005/highlight/true#M7931

...that mention to press F2 at POST. I've tried that, as well as every other F key on my keyboard. I've even plugged in a second keyboard to make sure it wasn't faulty or something, and none of it works. I am basically locked out of the BIOS and Windows 8.1. I'm currently running on a Live CD of Ubuntu (I can access all my drives, including files on my internal drive, so there's absolutely no problems with the disc drive or the hard drive themselves), so I'm not completely in the dark, although I'd really like to have access to Windows 8.1. I do have a USB with an 8.1 installer on it, although I'd really like to make sure I can reset my BIOS first before having to boot into Ubuntu once more and backup all my files (Which I'd hate to do, as I don't really feel like wiping right now). The 8.1 installer doesn't have an option to let me access the UEFI settings, either. All I have is a Command Prompt.

Is there any way I can force myself access to my BIOS/UEFI (Not sure what the proper term to use is here) and revert this change? Even if I can just reinstall the BIOS to reset it to defaults, or some kind of little loophole I can use (Like some kind of miracle Live CD), anything to keep me from wiping and reinstalling would be the best.

Oh and needless to say I probably won't touch that setting ever again after fixing this. I'll probably find some other laptop to install Ubuntu on as to not fry this one.

Accepted answers

TeamFail

So I decided to look into the BIOS update files, and I managed to extract the files from the newest BIOS update firmware using 7-Zip, then I manually installed the files using the applications that it came with, WinFlash32.exe within the environment that my W8 USB ran. It reset my BIOS settings to default and allowed me access to Windows again!

For those that have the same issue I had, do the following:

1. Install 7-Zip on a secondary computer.

2. Open the installer file (Mine was VA410218.exe) in 7-Zip (It's a 7-Zip self-extracting file) and extracted the files to a second USB drive.

3. Opened the launch.bat file in a text editor, then took the USBs and inserted them into my laptop and started up the Windows 8 USB. I went to Repair Windows, then opened a Command Prompt.

4. I typed in F:/WinFlash32.exe /bcp /sd /ver /cvar /v /endkey /silent /bbl /cac /cbp 30 /file F:/BIOS.cap, plugged in my laptop, then hit Enter. (NOTE: The drive, F, may change depending on your comptuer. Try a few different drives, and try the 64-bit version, WinFlash64.exe, as well.)

5. Let it do its thing, and it reboot, then flashed the BIOS image.

6. It rebooted once more, and properly rebooted into Windows 8.

All comments

JackE

Try this one for ideas if you haven't already. http://community.acer.com/t5/Notebooks-Netbooks/How-to-boot-back-to-EUFI-from-Legacy-BIOS-pressing-F2-getting/td-p/45467/page/2

Jack E/NJ

PS: I've got 3 WMWare guests on my puny little AO722 --- a SuSE, Win98SE & WinXP. And they share resources just fine....even when all 3 are running at the same time.

TeamFail

So I got to the cmd it mentioned, but it didn't find the exe files as anything that it could run. I then decided to boot the Windows 8.1 USB stick and try that cmd launcher, but for some reason, it wants to install the 32-bit BIOS and not the 64-bit version (I'm pretty sure it's 64-bit). In fact, the 64-bit application tells me to run the 32-bit version. Is this normal?

JackE

Is this an acer or digitalriver 8.1 stick?

Jack E/NJ

TeamFail

It's an ISO converted to USB. I put some thought into it this morning though, both applications should, in theory, install the same BIOS file. Or could it install a BIOS as 32-bit even though the system, I know, is 64-bit?

JackE

I'd feel more comfortable with the Acer-derived stick. But I know you're just itching to try what you got in hand. So I guess if you were able to create it using the MS tool, it shouldn't get you into any more trouble. 8^)

Jack E/NJ

TeamFail

I wouldn't say itching to use it, more like itching to get back my computer haha.

Edit:

Just tried the flasher, and it failed. It told me to update to the same type (2.X) of BIOS. It also gave me an Error 235 - OEM check failed from BIOS service.

JackE

Yup, sounds like you need to somehow feed the bios the 2.17 or 2.18 version.

Jack E/NJ

TeamFail

So I ran the installer for 2.X, and I get a 7-Zip error about %1 not being an executable file. Another live cd tells me that I'm not running the proper version of Windows.

JackE

>>> I'd really like to make sure I can reset my BIOS first before having to boot into Ubuntu once more and backup all my files (Which I'd hate to do, as I don't really feel like wiping right now)>>>

Sorry I have to ask this but...how do you feel about a Linux data backup and partition deletion right now?

IMO, messing with a stubborn UEFI bios at a lower level than you already have, is not advised since there seems to be no dos mode USB stick flash equivalent available for UEFIs from Acer at the moment.

Jack E/NJ

TeamFail

Well, I do have a 3 TB hard drive, so backing up my laptop would just take a few hours of my time. After I back it up, what would I do?

JackE

Some new ideas to try if you haven't already---http://askubuntu.com/questions/393954/cannot-access-bios-after-shifting-to-legacy-mode-lenovo-e330

Jack E/NJ

TeamFail

I couldn't get rEFInd to work, and I don't think I'm going to bother with gummiboot, although I'm looking at other boot manager CDs to see if I can find one that can reboot to the BIOS or start up the BIOS and allow me to revert my changes.

JackE

BTW, I googled a bit and found that Phoenix and AMI may offer a dos mode UEFI USB flasher for some of their products though I'm not too confident they'd work in their Acer-specific products. This UEFI technology stuff sure seems to have a lot of bleeding edge-type issues that haven't yet been quite ironed out.

Jack E/NJ

TeamFail

So I decided to look into the BIOS update files, and I managed to extract the files from the newest BIOS update firmware using 7-Zip, then I manually installed the files using the applications that it came with, WinFlash32.exe within the environment that my W8 USB ran. It reset my BIOS settings to default and allowed me access to Windows again!

For those that have the same issue I had, do the following:

1. Install 7-Zip on a secondary computer.

2. Open the installer file (Mine was VA410218.exe) in 7-Zip (It's a 7-Zip self-extracting file) and extracted the files to a second USB drive.

3. Opened the launch.bat file in a text editor, then took the USBs and inserted them into my laptop and started up the Windows 8 USB. I went to Repair Windows, then opened a Command Prompt.

4. I typed in F:/WinFlash32.exe /bcp /sd /ver /cvar /v /endkey /silent /bbl /cac /cbp 30 /file F:/BIOS.cap, plugged in my laptop, then hit Enter. (NOTE: The drive, F, may change depending on your comptuer. Try a few different drives, and try the 64-bit version, WinFlash64.exe, as well.)