dumb question:
whats malware?
Malware is a catch-all term used to designate the wide (and ever-growing) array of malicious code such as virus, trojan, spyware, adware and rootkits that can run on a computer without the user's consent.
Some posters seems way too eager to pressure newcomers into buying new hardware despite their problem having nothing to do with hardware.
Sure, a X1900XT along with a mid-ranged C2D, a high performance mobo and 2GB of DDR2 is a very solid gaming system and would look nice in a sig but the first thing you should do at this point is to eliminate any networking and software issue before you go spending your money on hardware.
While your CPU is on the verge of obsolescence (not quite there yet but very close to), a 7800GS (375/600, 38.4GB/s, 8ROP, 16PS & 6VS), even though it is an AGP card, is somewhere between the 7600GT (560/700, 22.4GB/s, 8ROP, 12PS & 5VS) and the 7900GS (450/660, 42.2GB/s, 12ROP, 20PS, 7VS), as such, it may not be amongst the top performers but it is very capable of providing an enjoyable gaming experience (even more so if you give it a bit of an overclock), it is worth taking measures to migrate it to a new system if you do decide that you need to upgrade.
In your situation, an hybrid AGP/PCIe motherboard (such as the Asrock 775Dual-VSTA) would allow you to use your 7800GS with a contemporary CPU (E6300 or E6400) yet give you the option to upgrade to a PCIe video card without having to change motherboards, same goes for transitionning from 2x512MB DDR to 2x1GB DDR2.