I installed an anti-virus program. Now yahoo boots up very slowly and I can't access my address

compose or forward. I am not using the beta program. Will installing the beta fix these problems?

I installed an anti-virus program. Now yahoo boots up very slowly and I can't access my address book from comviruses

Try this first:

You may possibly have a corrupt cache file -- it makes all KINDS of things go wonky. Try this: clear your history, temporary files (these will take a while!) %26 cookies, restart the computer and retry.

I installed an anti-virus program. Now yahoo boots up very slowly and I can't access my address book from comantispam

Are you sure it was anti-virus ? Seems to me some pro-virus thingy!