Windows 7 User account change reboot crash lockout


New Member
Feb 11, 2009
I've been running Win7 for a few weeks now on my Sony Vaio laptop. No problem. I went into the user account control area and reset the account control to the minimal setting. It asked for a reboot. Upon reboot the system is completely black screen with no HD activity. I can't boot from the CD. The CD spins up but then stops. It looks like a BIOS scramble. I am totally stuck and ticked off. Suggestions? :confused:

This is a Sony Vaio VGN-T91S. I am unable to use the F key to get to the bios setup. Interesting to hear the CD working for about 10 sec or so then stop. The most I get is a blinking cursor in the top left corner of a black screen. I never get to the Vaio logo.
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First, I'd power down the PC by using the button on the front of the PC. On restart, you'll be asked how you want to start Windows. Choose last known good configuration. If that doesn't do the trick, try the below.

Try hitting the F8 key on startup to access the options such as Safe Mode, Safe Mode with networking, etc.

Choose the top one, repair my PC, choose the Startup repair option first. If this doesn't work, you may have to use System Restore.

By the way, I've done this numerous times on my Windows 7 machine.
No Joy

I appreciate the suggestions, but you don't understand. I am unable to get to the BIOS screen let alone the Windows login screen. I get nothing but a black screen on reboot with a cursor blinking in the top left corner. I can't boot from a CD. I can't break to the BIOS and can't get to the Windows boot sequence. The computer is completely locked up. Ugly...
OK, gotcha,

I can't imagine why a change to UAC would render you PC unbootable.

So hitting the power button didn't bring up any screen?

Did you install any software or make any other modifications to your PC?

I didn't do anything other than change the UAC setting and reboot. This is a very stable machine. I've run XP Pro for years and had Win7 up for a few weeks with no problem. It feels like the BIOS got scrambled somehow. I can't imagine what else would make the machine unbootable. It's odd that the CD will seek for 10 sec or so then just stop. I get no activity light at all for the HD.
Well, I'd actually wait a while to see if other members have any ideas.

I do know of a couple things that will reset the BIOS to it's original state, but you'll need to remove the PC's cover to access the motherboard.

1. You can take out the battery and then re-install it. or
2. You can toggle the BIOS reset jumper.

I was thinking about pulling the internal battery to reset the BIOS so it's encouraging to hear you suggest it. The BIOS reset jumper is something I'm going to have to look into. Thanks again for the input.

Pulled the cover, pulled the internal battery and reassembled. BIOS reset and I'm back in. Amazing. Not sure what crashed it, but the BIOS reset worked. Thanks for the support.
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BTW, that SS in your signature is my son's dream car. He's been after me to find him one...
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