Now that they have told you what it is here is how from a few sites click on the links below for more information:
When you format a disk, you erase all its files and prepare it as if it were a new, blank disk. You can format a second hard drive or a drive partition in Windows. To format your C, or boot drive, however, you need to use DOS. The following describes how to format a hard drive using Windows 95/98 or DOS 3 or later.
Windows - Second Drive or Partition
Steps:
1.
Double-click the My Computer icon.
2.
Single-click the second drive icon to select it.
3.
Open the File menu and select Format. The format window displays the hard disk capacity.
4.
Select Format type and enter a disk label. If you want to start up (boot) from the second drive, check the "Copy system files" box.
5.
Click Start. Windows displays a warning box. Read the warning, and then click OK to begin formatting.
Warnings:
The format procedure deletes all files on the hard disk. This action is not reversible. Be sure to back up any files you want to keep.
DOS - C Drive
Steps:
1.
If you are formatting the C drive, you need to boot from a floppy disk and use DOS to format the C drive. Start the computer using a startup floppy disk (see "How to Create a Startup Floppy Disk").
2.
Turn on the computer. The screen should show the A:\ prompt.
3.
Type CD C: to switch to the C drive.
4.
Type "FORMAT C: \S \V". This command formats the hard disk, transfers the appropriate system files to make it a startup disk, and prompts you for a new name. The "\V" command is optional.
5.
Enter the new disk name.
6.
Eject the floppy disk and restart the computer. The hard disk is ready to receive files.
Warnings:
The format procedure deletes all files on the hard disk. This action is not reversible. Be sure to back up any files you want to keep.