|Your system is a dead end as far as upgrades are concerned. Very little from your old system would be useable. Maybe the drives, but that's about it.|
Your CPU is a socket A. That socket was retired long ago. Since then, AMD has gone thru the socket 754, 939 & AM2. The current socket in use is AM2+ or AM3.
Your RAM is probably DDR1. DDR2 is slowly being faded out & the newest boards require DDR3.
The 7600GS is an AGP card & AGP slots are ancient history, they have been replaced by PCI-Express x16. Even the PCI-e has gone thru a couple phases...the original was v1.0, v2.0 is currently in use & v3.0 is coming out next year.
And the old IDE hard drive / optical drive interface has been replaced with SATA. Most boads still have one IDE connection so you can still use up to two IDE devices, but SATA has taken over. And like PCI-e, SATA has already gone thru a couple of versions & a third is not far off.
In other words, you have a whole lot of catching up to do.