You're in a hard spot, the same one I'm in.
I have a system with similar specs that's with my parents:
Athlon XP 1700+
Epox Mobo
1 gig of RAM
NVidia Ti4200
I bit the bullet and spent $325 to upgrade to the following:
Intel Pentium E2180
Gigabyte GA-73PVM-S2H Mobo
2GB RAM...
I owned this monitor for approximately 3 months. The DVI port died after 1.5 months. I still wanted to use the monitor so I got a DVI-->HDMI adapter but after 2.5 months, the HDMI port started going out too!
Glad I bought it from Costco so I returned it in a hurry. It was a good monitor...