Computer system isn't working
Yesterday I installed avast 4 antivirus. However, today my computer started behaving differently. My mom said that a window came up and she kept just cancelling out of them. However, I cannot get AIM6, Windows Media Player, and Internet Explorer to work. Internet Explorer opens but it is weird with some sites and the Windows update function and other functions don't seem to work.
My regular computer functions do not work either, such as system restore, search, help and support, etc.
I'm using an xp, so does anyone know why my computer is bugging out?
(Also, I do not know what kind of windows were opened when my mom was using the computer).