thnx for u reply booger,i had tried with what u said,but the problem is still persisting.if i installed win Nt and then if i try installing win2000 pro, i am selecting leave the current file system intact and then proceed then win2000 pro is getting installed , if i try installing win2000 pro by formatting it's not getting installed.it's strucking at format, as i told before.if i did that after winNT and selecting keep the current file system intact then win2000 pro is installing.i couldn't guess where the exactly is the problem.can u help me in this.