Have a Dell laptop, started getting the start windows normally or repair screen, each option did nothing. Windows 7 64-bit and it's a DELL-Inspiron 15-3521 Decided to just reformat, didn't have anything important on it. After a lot of trial and error I'm lost, I deleted the partitions, got an error. I can't recall what it was, but now I have "disk 0 unallocated space 495GB", tried to create a new partition, got another error and still have the unallocated space. Now I open cmd, do diskpart, and the first time the unallocated space wasn't even listed, so I restarted and then it appeared. Now for disk volume all it shows it the windows 7 OS disk I have in there. But I can clean the disk 0 now, but when I put create partition primary, I get an error about I/O device. Now when I got out of cmd seeing how I was lost now, there was a warning about "Windows cannot be installed to this disk." When I open it "This computer's hardware may not support booting to disk. Ensure that the disk's controller is enabled in the computer's BIOS menu." The BIOS for this laptop is pretty vague, I don't see anything about SATA, it's a refurbished laptop so if you guys can't come up with anything I'll just get a new HDD because it might have just been a bad one.