Acer aspire 6920 startup problem (Windows Error Recovery)

Hi
I’ve had my acer 6920 lap top for around 2 years now and its worked great. But recently I installed a game (Sims 2) which said it had some compatibility issues with my version of vista and gave me the option to fix the problem or run the game anyway. Since my brother got the same message on another computer when he installed the game, didn’t fix the problem, and it worked fine I ignored the "fix" message and played the game with no problems.

That night I turned the computer off and everything seemed fine. the next morning I tried to turn it on again and it said "Windows Error Recovery" with 2 options "launch start-up repair" or "start windows normally". no matter what option I pick it ends up restarting itself and bringing me back to this page. I went to "advanced boot options" but every action leads to the same end. I noticed a blue screen with writing on it flash up each time just before it restarted itself so I disabled automatic restart found that it was this message:

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a problem has been detected and windows has been shut down to prevent damage to your computer

if this is the first time you have seen this stop error screen, restart your computer. If this screen appears again, follow these steps:

disable or uninstall and antivirus, disk defragmentation or backup utilities. check your hard drive configuration and check for any updated drivers. Run CHKDSK /F to check for hard drive corruption, and then restart your computer

Technical Information:
*** STOP: 0X00000024 (0X00190444,0X86EC3A88, 0XC0000102, 0X00000000)

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I have tried to find out how to follow the steps given but most of them require the ability to get onto windows and log on. I would like to return my computer back to working condition with my files intact but I am good at backing up my files so there are only a few files that I need to save, then I will have no problem reformatting the hard drive.

any help will be greatly appreciated

thanks a lot

Adam