|Install a fresh copy of Windows 7.. Did you also get the Windows 7 install media and/or recovery disks? Make sure you have a Windows 7 product key sticker on the workstation, so you have the product key for install. |
How to install Windows 7 (with screenshots): http://www.door2windows.com/how-to-...
Do a custom install, and delete all partitions, so it shows DISK0 unallocated (just like the screenshot) and move forward with install. If you dont have the Windows 7 media, let me know what version of Windows 7 you are running and can provide you a ISO..