Windows XP altered by AVG

I don't think I have a virus. I think that AVG antivirus altered my IE and windows xp so that I can't use a lot of the functions.

I think so because it happened the last time I downloaded AVG and I had to reformat (but I had forgotten). The same exact problems have occurred after downloading AVG again.

IE won't load email or facebook
I can't print from IE (but I can print from ms Word)
I can not add user accounts (the page loads blank)
I can't use the search tool to search for files and folders.. it loads blank
I am sure AVG messed up other files, but I have not tried them all.

I uninstalled AVG, but that did not fix the problem. I am told that there is no trace of AVG left on my computer. HOwever.. what ever AVG altered, has caused these problems.

Is there a way to fix the damage with out having to reformat?
Thanks so much