Free up disk space. A hard drive that is close to being full will drastically slow down your computer. You can clear up space by deleting temporary internet files, empty your recycle bin, remove programs that you do not use, put important files on an external hard drive.
Another way to free up disk space is to use "Disk Cleanup" on your Windows PC. To do this, click "start" and go to "Accessories", go to "System Tools", and click "Disk Cleanup".
Scan for Viruses, Adware, and Spyware. These nasty programs can slow down your computer worse than anything. I would recommend purchasing software that can remove all three of these common problems.
Don't automatically start up programs when you turn your computer on. Close any programs that you do not use that open when you start up your computer. These programs will run in the background and steal RAM (Random Access Memory).
Defragment your hard drive. Defragging your hard drive places all of your information for each file in one place.