Window XP wont format hard drive

I want to format my hard drive - WD 120. I get a message that Windows cannot complete format. I tried DOS with 'FORMAT' command, I get a m essage that 'someone else" or another application is using the hard drive. I have not yet found that someone else or the other application - any thoughts?

I had this too.

try this. Goto microsoft.com and search for Windows XP Boot disks, there should be 6 of them. Make the 6 floppies, insert the first floppy and restart. It'll walk you through all 6 disks, and let you install, format etc without booting up your OS

Thanks gravity. I will give a shot.

I tried the floppy start, but at the end i got a message that the hard drive could not be formatted.