Check a drive for errors

Disks can sometimes develop errors in the way the files are stored, and those errors can affect system performance. Disk errors sometimes manifest themselves in odd ways--everything from missing files to out-of-memory errors.

There are two types of disk errors:
a). Physical: A physical error is a bad spot on the disk, usually caused by physical trauma such as dropping the computer while it's running.
b). Logical: A logical error, which is much more common, is an error in the table of contents of the disk's storage system. The Check Disk utility in Windows XP can fix both types.
To check a disk for errors:
1) Open the My Computer window.
2) Right-click the hard disk (or one of them, if you have multiple hard disks) and select Properties.
3) On the Tools tab, click Check Now to open the Check Disk dialog box.
4) There are two options available:
4a) Automatically fix file system errors: If you select this one, Check Disk will fixe any problems it finds rather than prompt you about each one. Beginners should mark this; advanced users who are curious about what errors are found may try other one.
4b) Scan for and attempt recovery of bad sectors: If you mark this one, Check Disk does both a logical and a physical test. Because each physical test takes a long time (an hour or more in some cases) and because physical errors are less common, most people use this option only occasionally (once every few months or so) or only if a disk read or write error has occurred.
Click Start to begin the check. If you didn't mark the Automatically fix file system errors checkbox, and if any errors are discovered during the check, a dialog box appears asking whether you want to fix them. Click Yes to fix each error.

Don’t forget to repeat this utility once a month.