As many as needed.
In laptops/notebooks there is usually only one hard disk.
In a desktop or server there could be potentially any number of disk drives.
If you mean a CD/DVD drive the same applies.
In some, no disk drives, most 1, lots 2 and in servers and workstations, up to 72 physical drives. Floppy disks, hard discs (IDE, SATA, SCSI, SSCSI, PATA, EIDE, ATA, MFM, RLL), solid state, zip drives, USB drives, and CDROM/DVD.
To fix a computer disk drive you just put some glue on the disk.
Hard drive, Disk drive and FLoppy disk drive
The disk drive
The "A:" drive is the first floppy disk drive.
A disk drive is a device that computers can use to read and write information on computer disk. An example of one is the hard disk drive.
A computer floppy drive is the device that reads and writes to a floppy disk. It is located on the front of the Computer.
If you have an older computer the 3.5" floppy drive fits into the disk drive. Newer computers only have "cup holders" for CD or DVR disks.
Hard disk drive.
Optical disk drives are also known as cd roms for your computer. They allow you to store data and burn information on them from the disk drive slot on your computer.
A computer hard disk or hard drive (fixed disk) is hardware.
A disk!
the disk drive if you have a computer you might want to buy a disk drive they are big hugh machines