Sounds like you have hard disk errors. Use
Advanced Boot Options to select Repair Your Computer and get to the
System Recovery Options. Then select the command prompt. Do the following:
chkdsk /r c:
chkdsk /r d:
chkdsk /r e:
chkdsk /r f:
.etc until you get the message that the volume could not be opened for direct access. For any drives that do not give the message:
Windows has checked the file system and found no problems
run disk check again as above. In other words, if it says:
Windows has made corrections to the file system
after running the disk check, run the disk check again.
I realize you may only have one disk show up in Windows explorer, but you may have more than one disk through recovery options. This is because the system creates a hidden boot partition (which will be C: in recovery), you may have a recovery partition for your PC that is hidden (which will be D: in recovery), and you will have your primary Windows partition (which may be E: in recovery). A custom PC will likely have at least C: and D: to scan.
Also, if asked whether you would like to force a dismoount on any volumes, choose Y for yes. That message just means the volume is currently being accessed, but dismounting it will not cause any harm.
NOTE: If the Advanced Boot Options will not work:
System Repair Disc - Create