It looks like when you have changed the optimal settings to Y the onboard Display adapter has been re enabled (would have to be disabled for the vodoo card to work).
Look through the BIOS (you can see this still?) and disable the onboard display adapter this should get you going again.
If this dosnt work the next thing to do is remove the hard disk and connect it up to your new machine as a slave drive then get your files that way.
hope this helps
ASUS A7N8X-X mainboard
Athlon XP 3200+
1 GB Ram
120 GB HD (IDE)
250 GB HD (IDE)
128 MB Radeon 9800 PRO with custom H/S fan
8 x DVD Writer + DVD ROM
8 Meg ADSL (with ****ty ISP Bulldog)
Mystify Mamba mouse
And still ****ty fps in CS Source.