Fidoliedo

If you were able to delegate rights, you may have removed all the rights from the drive disallowing access. If you can see the drive, right click on it and go to sharing and security. In that window, click on the security tab. If there are no users in the GROUPS window, you can click on ADD and add the administrators group to the folder and click apply.

If you can't add a user, then click on ADVANCE, click on OWNER, highlight ADMINISTRATORS, check REPLACE OWNER ON SUBCONTAINERS AND OBJECTS, and click APPLY.

If you can't even see the drive or there's no drive letter, make sure the system see's the drive by going to COMPUTER MANAGER, DISK MANAGEMENT. If the drive is there but with no drive letter, right click on the colored box to the immediate right of the drive and select CHANGE DRIVE LETTER AND PATHS. Select an unused drive letter and you should be good. If the drive is there and says UNALLOCATED, you just dumped the partition. Don't panic, get a program called FILE SCAVENGER 3.x and that will do a wonderful job of restoring that drive. I can't go into details about that program, but you will need to restore to another HD as to not overwrite those files on the dumped drive. The program is fairly cheap and so worth the price.