hard disk 
noun Computing
A rigid non-removable magnetic disk with a large data storage capacity.In the computer realm, magnetic recording is used on floppy disks, hard disks and magnetic tape as the main method for data storage....
- Some have multiple IDE or SCSI hard disks for massive storage, and some have only one IDE or SCSI drive.
- If your computer is infected with a boot sector virus, the virus tries to write copies of itself to the system areas of floppy disks and hard disks.
- extrachromosomally
- extraconstitutional
- extracorporeal
- extra cover
- extract
- extractability
- extractable
- extraction
- extractive
- extractor
- extracurricular
- extracurricularly
- extraditable
- extradite
- extradition
- extrados
- extradural
- extrafamilial
- extrafloral
- extragalactic
- extra innings
- extrajudicial
- extrajudicially
- extra large
- extralegal