Here are some tricks on how to speed up your computer:
1.Defragment your HDD.
2.Scan your HDD for errors.
3.Scan your computer with an antivirus updated with the latest definitions.
4.Scan for spyware and adware.
5.Adjust visual effects.
6.Stop unwanted programs from Startup menu.
More information you can find
here.
You can read on
Microsoft webpage another article on how to impreove your PC performance.