AVG free is a very good program.  Used it myself for awhile until I decided to purchase AVG for my Vista Home Premium.  They never tell you that you are infected.  Or, try to force you to buy their paid version.   Perhaps it is time for you to look elsewhere.  Avast is another I heard that offers free download.  Not familiar with it but, it is just another choice.  No matter which one you decide to use always be careful with anything downloaded.   Also, you might want to try an optimizer to keep your computer 'clean'.  Good luck.