Go
Control Panel -> Administrative Tools -> Computer Management ->Disk Mangement and Click on "Rescan Drives" and it should show up as unpationed space and ready to format
But this is only if your mobo can support 48-bit Lba drives.
If your mobo doesn't support 48-bit lba drives even with a bios update, for eample with seagate drives you will need to reinstall windows, but first use Seagates Disk Wizard to enable Dynamic Drive Overlay (DDO)
More information here on DDO
http://www.seagate.com/support/kb/di.../use_dwse.html