dren

Try doing a low level format, make sure all the partitions have been deleted properly. Get some drive diagnostics utility from the drive manufacturer to make sure everything is clear as far as the partitions and to do the low level format. If you still have trouble you might be able to use a drive overlay to force your computer to see the full size. Really though, if you do a low level format and your cmos is up to date with the correct version, it should detect OK.