Internal Hard Drive does not have a drive letter but used to.

1) Open a Administrator Command Prompt
2) type DISKPART
3) type LIST DISK
4) type SELECT DISK # (the disk No)
5) type LIST PARTITION
6) type SELECT PARTITION 1
7) type SET ID 07

I have a seagate portable hardrive (1tb) but the problem it not showing up in the computer and when i go to the disk management and it was their but not initialized but when i try ti initial it the poup message appear and it say (The request could not be performed because of an I/O devices error

Thanks need your help plizee

theog, that looks like it could have worked but stupid me i already formatted it through diskpart and it brought the drive back but lost the files. Then again it might have already been formatted since it showed it was empty when it should have shown it was half full. That was a bizarre problem, thanks for all the help with this. :)