1. Regularly Backup All Of Your Work.  Backup your files on a CD, pen drive or other device to prevent data loss.

2. Keep All CDs That Came With Your PC.  Your recovery CDs can contain specific driver software unique to your PC.

3. Defrag Your Hard Drive Monthly.  When you add data to your hard drive, it is placed in the first available empty space on the drive regardless of whether or not that space is large enough to accommodate all of it.  The part of the data that would not fit in this first empty space will then be placed in the next available space, and so on, until all the data has been placed on the drive.  This results in fragmented files.  When you delete data, that space on the hard drive becomes empty and this space will be filled, bit by bit, with any new data that is added.  Over time, through adding and deleting, a large amount of data becomes fragmented.  This results in increased seek times because the hard drive has to look in multiple locations to find all of the data concerning a particular file.  This means it will take your computer longer to find and open files. 

4. Keep your Tower Unit Off The Floor.  The dust in your carpet will be sucked in by the computer fans, causing the inside of your computer to fill with dust.  It is best to raise it up off the floor at least 12 inches. 

5. Always Shut Down Windows Correctly.  Use the Windows menu to shut down correctly and avoid data loss or corruption.

6. Organize Your Files And Folders.  Keep your files and folders named and dated so backing up and finding files is a lot easier. 

7. Shut Down Before Removing Devices.  External devices disconnected within Windows can cause malfunctions. 

8. Keep Your Desktop and Startup Clean.  Remove unwanted desktop items and start programs to improve performance.

9. Install The Latest Windows Updates.  Make sure your computer is set to receive automatic Windows updates from Microsoft.  These updates contain the latest security patches and service packs. 

10. Install A Good Antivirus Program.  I recommend the free version of AVG8.  Download this program from a safe website like cnet.com.  Then make sure you do a full system scan at least twice a week.  Also, some people think installing two different antivirus programs will keep their computer safer, but that's not true.  Antivirus software, some more than others, tends to make your computer run slower.  So, if you install two different programs, your computer will run even slower, and you run the risk of the two programs causing conflicts in your system.  One is enough.