The easiest way to speed it up is with the following three steps.
#1 Remove any unwanted programs off your computer.
#2 Remove any unwanted files, images and documents and delete all the temporary internet files.
#3 Defragment your hard disk. You can find this under system tools in windows. This will put all the program files in order and speed your computer up.
#4 Run a registry cleaner and get rid of the spyware, junk and links to programs that are no longer installed. The registry has a limit on the size and the bigger it gets the slower your computer will become.