1. On the command prompt type diskpart and answer to any possible UAC prompt.
2. On the new diskpart prompt, type list disk. Note the Disk ### column.
3. Type, select disk ### (with ### being the disk you wish to delete. Usually the disk with partition 0 with a size of 200 MB)
Finish by typing, clean.
4. Type exit to exit diskpart
http://superuser.com/questions/47359/ho ... -windows-7