|Hmm...LOL! I would first download and run (free) Super anti spyware , Malwarebytes or spybot and check for bots , trogans and other nastys.|
Then I would take a look at what programs are running on your computer.
Not knowing what programs you have this is just an example.
Some people have MS Office, IE explorer, and every program they have installed running.......thus taking up resources.......
Find out what programs are running at start up (hint.. Free winpatrol is easy to use) Stop the unnecessary programs from starting at boot up..
Some house cleaning may also be in order...IE temp files