This is an excellent little app, it actually shuts down AVG so you can play games without internal lag.
It also has a ton of other apps built in to help you speed up your pooter.
And heres the best part, its free.
I highly recommend it if you have AVG, or just want to speed up your machine.
http://download.cnet.com/Game-Booster/3001-18512_4-10913645.html?spi=d03a1541b22dd8a16a71b0fe8c28f5c6 (http://download.cnet.com/Game-Booster/3001-18512_4-10913645.html?spi=d03a1541b22dd8a16a71b0fe8c28f5c6)
Once the page opens, don't click anything, be patient and wait for the save box to open.
Click save and once it downloads, just open it up and follow the prompts.
This thing really made a monstrous difference in how my games run.
Well worth the download...