I don't see anything wrong with your system specs.
Have you tried all the obvious stuff like rebooting your computer, making sure nothing is running in the background like virus scanners,etc? Also do a full scan from the patcher to make sure you don't have any corrupted files.
I don't know of any client crash bugs right now that would explain such a frequent crash other than the out of memory errors people experience in some zones when running Windows Vista.
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(Rothgar) Re:On going crashes....
