Heres my problem: I got this computer about 2 years ago. It was "decent" for its time, like it was prett average. Then I got into gaming, and I needed all the latest hardware to play CSS at top notch graphics, or play CoD4 or crysis. (Or the upcoming Starcraft 2 hehe) Okay so one day (last week) I installed Vista, my friend paid me 50$ to try it out before he puts it on all his computers at work.

So a few days goes by, I installed AIM, Winamp, Steam, Xfire, Firefox, thunderbird, Azereus, limewire, and poweriso. My normal programs. Everythings all good and well for a few days, then the one day I went to go listen to some music. So i click on winamp, and nothing happened. I clicked on Windows Media Player, and nothing happened. Hmmm I said. So i started trying to open other programs, and nothing came up. So I figured I'd restart my computer! Yayy itll fix everything! Well now it wont start up. It brings me up to a black screen saying: This bios is made exclusively for acer computers, and it shows my master and slave drives, and under that it says CMOS Checksum error. It says to go into CMOS and reset processer frequency rate or something along those lines. And at the very bottem it says Press F1 to continue, or DEL to enter setup. But my keyboard is unresponsive! I tried 3 different keyboards on all USB ports, and even used a USB to PS/2 adapter and tried the 2 PS/2 ports. I tried resetting BIOs (by taking out the battery and reinserting it) and I tried to start up the computer without my Nvidia 8600 geforce XFX video card. Idk whats wrong with my computer, it just wont respond to my keyboard or let me get past that screen with it saying CMOS Checksum error. Can you guys help

Can anybody help?

Is there a CMOS jumper next to the battery?

Also might try a new battery.

CMOS checksum errors

Explanation: A checksum is computed as an error-detecting code, to protect the BIOS settings stored in the CMOS memory. Each time the system is booted this number is recomputed and checked against the stored value. If they do not match, an error message is generated to tell you that the CMOS memory contents may have been corrupted and therefore some settings may be wrong. BIOSes react in different ways to encountering this sort of error. Some will warn the user and then continue on with whatever settings were in the CMOS. Others will assume that the settings that were in the CMOS were corrupted and will load default values stored in the BIOS chip "for safety reasons". The error message will indicate which your system is doing.

Diagnosis: The most common cause of checksum errors in CMOS is a battery that is losing power. Viruses can also affect CMOS settings, and motherboard problems can also affect the stored values.

Recommendation: Follow the instructions in this section to address the CMOS corruption. You should make sure that all of the BIOS settings in the system are correct, by rebooting the system, going into BIOS setup and double-checking all the values (hopefully against a recent BIOS settings backup).

http://www.pcguide.com/ts/x/sys/booterrGBER08-c.html

If you get past this I would remove Vista and reinstall the original OS provided by ACER.