I am running windows XP/2 and Firefox.. When I surf to yahoo.com and log in my screen goes blank (all grey actually) as does all of my other open windows. I close Firefox and reopen it and revisit yahoo.com my screen will come up normally but all of my other windows will remain greyed out until I close them and then reopen. Any ideas on how to fix this?

It sounds like you have driver issues. One problem you may be having is that XP has been upgraded to SP3. Your still on SP2. I suggest you upgrade first. It's a free service. Then update any drivers for video etc and sound drivers. Then try again. A lot of webware assumes you have the latest version.