Hi
and welcome.
Do you need to completely wipe the hard drive that you are using, cause if so you will lose or your data?
If its an empty hard drive that needs formatting then do this
Start - Control Panel - Administrative tools - Computer Management - Storage - Disk Management
You will see a table with Disk0, Disk1 etc, just right click on the drive you need to format and click format.
REMEMBER you will lose any data that is on it, so if its important back it up.