Basically, it scans your computer files, allocation tables, and the surface of your hard drive to look for errors. When it finds them, it tries to fix them (if the you have that option checked).
It can take up to an hour to run this program and you don't want to be doing anything else on the computer while it's running. Like Defrag, you should also run this program once a month.
In Windows XP, Microsoft renamed Scan Disk to Error Checking. They also changed it so you had to reboot your computer to make it run.
Close all programs on your computer and follow the steps below to run Scan Disk (or Error Checking).
Windows XP
1. Double LEFT click MY COMPUTER to open it.2. RIGHT click on the "C" drive and select PROPERTIES.
3. Click on the Tools Tab.
4. Click on the button that reads, Check Now next to Error Checking.
5. Place a check mark in both boxes and click START
6. Click YES on the message window that pops up
7. Restart your computer
Scan Disk will run after you restart your computer. It will take about an hour for it to complete. When it's done, you see your computer desktop again.
