Vista - Windows Explorer

Hello All. I am having a problem. It seems that my computer is telling me
that my windows explorer has stopped working, then it tries to restart my
computer. I have been able to fix it so that I can still use the internet
through the windows defender, but the Microsoft Windows messege still keeps
poping up ever few seconds.

I have downloaded an anti virus program that said I had three viruses and
have been quaranteened now but I can't access anything on my computer but the
internet. How do I get this solved.

I have run out of solutions. Please help.
Thanks.