Want to reformat my hard drive

[DLD]

My computer is sick and I want to reformat my hard drive and start clean. I went to the dos prompt command and typed in format c:.  That I understand.  The problem is the computer tells me it won't because of the volume is being used or something.  It asked me if I wanted to force the dismount and I said yes.  Got a message telling me it didn't work. 

I don't know what to do.  Would appreciate any help from the pros!

Thanks!

DLD

[xavier]

Yo didnt say what OS you are using, If XP left click on my computer,right click on your drive & click on format

[patio]

You cannot format your C: drive from within Windows.
Simply boot to the XP CD and at the prompt select Setup/install Windows...it will give you the option to erase your partition and create a new one very early on in the install...select Yes.

WARNING: ALL data on that drive will be gone so do your backups first...