Ok, since i'm not an expert, I'm gonna describe everything i did:
Hitted Del at Startup, then I hitted advanced setup -> First reboot CDROM, placed the CD in the rom, then hit F10 (save and quit). Then it rebooted and went dark and said:

" Couldn't open drive multi(0)disk(0)rdisk(0)partition(1)
NTLDR: Cannot open drive multi(0)disk(0)rdisk(0)partition(1) "

Then i thought that the cd was broken or something and putted it out and rebooted, THE SAME ERROR AGAIN. Went to Advanced Setup again, changed the "first reboot" IN EVERY SINGLE WAY, AND ........
-> NOTHING, again the same Message, Went back, hitted DEFAULT VALUES, but the same kept showing....
WHAT CAN I DO ?????????????
HELP !!! PLEASE !!! I LOVE MY PC !!!!