Im sorry for the late replay, but i made a research and the drive i have the problems is a Fujitsu MPG3204AT - E, i installed it has a second hardrive on this pc, and formated it, i made also a scandisk to it and found 0 problems, no viruses with a scan has well.
Then i went to the properties of the controler and it says that is a MPG3204AT -E SCSI Microsoft Controler, so...is this 20GB Hardrive SCSI?? cause the main one on this PC is a Seagate 40GB SCSI and i need a ATI Board and controlers to make it work properly...dont i need to install the same thing to the fujitsu?

I can explain a few things has well, to make all this clear.
The actual pc im using ( this one ) has a VIA motherboard and originaly had the fujitsu hardrive. It was a gift.
My old pc ( the one that now has the fujitsu hardrive ) has a old motherboard INTEL BX i guess with a PII 333hz, had the Seagate hardrive with the ATI board.
So has the PC with the VIA is a PIII 800Hz, i tought in putting the 40GB in it, has its the best pc, and the fujitsu on the other.
Now, after all this..i dont know if it was a good idea.
Do u guys think that if i invert things, has they were, the drive will work fine on this pc?
Cause the scandisk, the anti-virus found no problems once so ever, so...the hardrive has the correct disk space avaiable, etc...so, at this first sight, evrything seam ok....

Hum..what u think?