Can not boot my Aspire D250

Hello,



When I try to start my Acer Aspire D250-1151 I get the error message "Windows could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SYSTEM"
When I try to reload windows from my external CD/DVD drive I get the error message
: "A problem has been detected and windows has been shut down to prevent damage to your computer. If this is the first time you've seen this stop error screen, restart your computer. If this screen appears again, follow these steps:
check for viruses on your computer, remove any newly installed hard drives or hard drive controllers, check your hard drive to make sure it is properly configured and terminated. Run CHKDSK: /F to check for hard drive corruption, and then restart your computer.
Technical information:
*** STOP; 0x00000007B (0xFA9063C,0xC0000034,0x00000000,0x00000000)"
The problem is that I can not get to a "C" prompt in SAFE mode or boot the computer in any way. I'm sure that it is a virus but I can not load any anti virus programs. When I try to run any of the suggested "fixes" they will not boot. Many of the web sites I have visited suggest that you use "Alt F10" but this will not work or any of the other variations suggested.