Hi searching4sanity,

First of all AVG is still free: you just need to get version 7.5- 7.1 is now discontinued.

Second, if you have AntiVir and avast! on your system, they will conflict and cause problems. Decide which AV you prefer, stick with that one and uninstall any others. See if the problems persist.

Yahoo! has a spam/virus filter: make sure this is turned on.