Re: Serious Computer Problem!!!
If you've not been in the back of the Computer and the floppy light is on all the time, then this is a classic sign that the computers locked up before post boot is performed and with this type of problem there are several different reason why it's not booting.
As you've got an onboard graphics card, which is using the main computers memory, check to see if the memory is seated correctly.
Also if you've been messing in the bios (for overclocking etc) try resetting the bios and see if that helps.
Post back with your results.
AMD Athlon 64 X2 Dual Core 4200+
DFI LanParty UT RDX200CF-DR Crossfire Motherboard
OCZ 4GB (4 x 1GB) PC3200 Dual Channel Platinum Series CAS2
ATI Radeon X1950Pro - Crossfire Edition - 512MB GDDR3 x2 cards installed.