If you have a windows install disk, then download active kill disk.
You need to erase the hard drive the right way, you don\'t format from NTFS to NTFS to erase a HDD.
Here is a free eraser, but you need to burn it to a **** and boot to it so it runs in DOS.http://how-to-erase-hard-drive.com/downloadfree.htm
You can also go to Western digital and use the tools for HDD to erase.
Once the HDD is erased, your clear CMOS, reset the setting in the BIOS such as boot order, you should be able to reinstall windows and install all the correct drivers.