Today's hard drives rarely have errors, so you probably don't need to check for any. But if you think your hard drive's acting strangely and defragmenting it doesn't fix the problem, tell Windows XP to check it for errors. Open My Computer, right-click on your hard drive, and choose Properties. Click the Tools tab and click the Check Now button. (Leave the two options blank.)

Click the Start button, and you hear your hard drive whirring away as Windows probes it for problems. If it finds any, follow the Windows instructions for making repair attempts. Also start saving your cash and backing up your data -- repeated errors mean your hard drive may be on its last legs.