I thought my computer would be able to handle WoW with 3 instances @ its lowest possible settings.... and i mean even 1x anti-sync
Use Piriform - Download CCleaner, Defraggler, Recuva, Speccy - Millions of users worldwide! for ccleaner and defraggler, and change your start up programs. There's no way you need that many processes going on at one time. By keeping programs that auto-start to a minimum, you can eliminate a lot of that bulk without fear for damaging anything.
I have both lol. I also have Tuneup Utilities which has a more advanced CCleaner startup manger. Guess I should use em and my harddrive was defragged yesterday
You Memory and Processor aren't the bottleneck, it should be running better than that. Turn off a bunch of the applications that you don't need, make sure that not only all of your wow clients are running at low settings, but also maybe set the resolution down to like 800 by 600.
You should just format. Make it nice and clean. And install XP because you only have 4gigs ram so no need for 64bit. And XP will use a lot less resources then Windows 7.