As a Christmas gift, I received a new 6TB hard drive, however I was short one SATA cable. So, I unplugged one of the hard drives that was already in my computer to test the new drive to make sure that there is no issues. The person who gave it to me said he bought it off of eBay, and the sellers page said it was a new drive. This was not true, because it came pre-formatted as exFAT. I would like to format it to NTFS just to wipe out any remnants of whatever the seller had on the drive before, but as the title suggests, I cannot format it. I figured that I would figure it out later when the new SATA cable that I ordered comes. When I plugged back in the old drive, Windows was reading it as RAW. I fixed this by running chkdsk, and all information seems to be there, however, most of the programs I had loaded on the drive no longer work, they give me a variety of error codes. I thought I would just loose the data and format the drive, but now I cant format this drive either. For both drives, the 'Format' option in Disk Management is greyed-out. If there is a way to salvage the data on the old drive, that would be great, but it is not super important, and can be replaced. The old drive is 1TB (and is full) and I plan to keep it in my system and continue to use it. Any suggestions about how to format both of these drives is greatly appreciated.