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 XP1. 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
Windows Vista & Windows 7
If you're computer is running Windows Vista or Windows 7, then note that Scan Disk has been renamed, "Error Checking" - but it's the same program. Follow the steps below to run Scan Disk (a.k.a. Error Checking) in Windows Vista and 7:
- Click the START Button and then COMPUTER
- Right click on the C-Drive and select PROPERTIES (you should see a new window like that below. If you don't, repeat this step until you see the window below).
- Click the tab that reads, TOOLS
- Under the heading, Error-Checking, click the button that reads, CHECK NOW
- Click CONTINUE on the pop-up message
- Make sure there are checkmarks in the two boxes and then click the START button
- You'll have to wait a few minutes for another window to pop up, but when it does, click the button that reads, SCHEDULE DISK CHECK
- REBOOT the computer
It will take about an hour for it to complete. There are 5 stages in this process and the last stage takes the longest. I like to run scan disk while I'm sleeping or know I'll be off the computer for hours. When Scan Disk is complete, you see your computer desktop again.