PLEASE help me! Computer won't boot!

[SocceRich20]

Ok, I just re-applied my thermal grease, and booted into Windows fine. I have a 2.8C and an IS7. I check temps, and they are normal, around 44C. Then out of the blue, my PC shuts down. I try to reboot, and I get into BIOS, and make sure everything is OK, and reset it to safe settings. When I reboot, I get A very long BEEEEP, and it stops after about 7 seconds, then does another, and doesn't go anywhere. I don't think anything has fried at all. There is a storm going on right now, but I don't think anything fried or broke. What should I do? I tried clearing CMOS, by putting the plastic thing up one space. When I flip the power supply switch, the green light comes on, but when I push the power button, nothing happens. When I kill the power, and put the plastic thing back in the right place, I get the same LONG beep when I boot up. Please help me ASAP!

[Bovon]

Try reseating the RAM...it may have become loosened when you wrere fiddling with the heat sink & thermal grease. The only other thing I can think of that will cause a long beep is BIOS problems. Try setting the BIOS to default..there is a 3 pin jumper on the board..either close to the battery or the BIOS rom chip..the jumper will be on pins 1 & 2...take it off (with the computer totally off, and the power cable disconnected at the back...very important) place the jumper on pins 2 & 3 for about 3 minutes..return the jumper to pins 1 & 2, and reconnect the power cable, and fire it up and see if that helped. Check the motherboard manual for the location of this jumper...usually called CMOS jumper or reset etc.

[imac9556]

yeah, try the suggestion that Bovon said.
If that does not work, try taking the whole system part. Build it outside the case on a non conductive surface and see if it works... last weekend i had the same problem and found out it was BAD ram.. exchanged it and its up and running..