5 boxing.

[Talos]

Get a SSD to have much faster access to data resources, and get 4GB of ram. That PC *can* 5-box, as I 5-boxed for a year on this machine:
E6600, 4GB RAM (only WinXP 32-bit though), RAID0 2x 36GB Raptors, 8800GTX.
Now, a 5-boxing machine can be done cheap.. just upgrade that E6850 to a Q6600 (make sure your motherboard supports it though), get 8GB of RAM, get 64-bit Windows, an SSD (even a cheap $100 will be better than any HD for hosting WoW), and a newer videocard.

I took the liberty of making a small shoppinglist for you based on my opinions and Silencers opinion
http://azerty.nl/winkelmandje/winkel...egen=1&product[245945]=1&product[91501]=1&product[34543]=1
(The SSD is optional, its the cheapest one that still has a high read speed (writespeed is slower though))

You current motherboard is capable of using the Quadcore processor and the memory i linked according to the Gigabyte website http://www.gigabyte.com.tw/Products/...ProductID=2543

Let me know what you think of it