I had an issue tonight when reinstalling w7 where the install would not let me delete the partitions on one of the disks… they could be formatted, etc, but the delete button was grayed out for some reason. Why it did this, I can’t tell you. What I finally found to fix it was this:
- on the first welcome screen of the w7 install, hit shift-f10, this gives you a command prompt
- run diskpart
- list disks
- select disk 0 (if this is the disk you want)
Then you can continue with the install on a new fresh and clean drive.