Below can help you speed up your pc:
1. Click Start, Programs, Accessories, System Tools – run Disk Cleanup
2. Temporarily close Quick Launch:
Right-click on the Taskbar, click Toolbars, deselect Quick Launch
3. Open My Computer
Right-click on C:
Click Properties
Click Tools, select Error Check (check all and fix), when finished click defrag & run.
4. Click Start, Run ipconfig -renew (type ipconfig space renew)
5. Restart. Right-click on Taskbar, click Toolbars, select Quick Launch to restore
All these things should be done regularly. The more frequently they are run, the less time they take.
-Note: Games and videos are mostly graphics. Graphics create large files. If these suggestions don't help, you might need more memory.
Last, if you haven't cleaned your registry in a while. This is necessary. Your registry holds all the information regarding updates, installs, un-installs etc. Each one of those events produces a key. That key needs your PC's resources and free space. So, if you clean your registry, you make more resources available for speed. Does a registry scan if you got more than 20 errors you should clean it.
http://toptenantispywareviews.com/RegComputerSlow_why.htm