@ Pualpsomaidis
Remove the V5 ? don't think so
just uninstall the ATi cards while using the 5500
That what I always do with my X1900's when they need a driver update
then I will always have a VGA card to co-operate with
when the ATi's are instaled just switch to them and continue, thereby is that the 3dfx card is very handy for updating Primary VGA's
When updating the 3dfx card uninstall it's driver switch to the ATi card install the 3dfx cards manually then reboot, then switch to the 3dfx card and install Voodoo Control as control panel and problems are solved for the 3dfx card
and when all is done you would get this as a result:
with a GeForce 6800GT the result is almost the same , only difference that a GeForce has 1 Ramdac for both outputs so you would only see VGA 1 as VGA 2, with the ATI it's VGA 1, 2 & 3 since that Radeon 9.xx and grater have 2 ramdacs one per VGA or DVI output and VGA 3 is of course the 3dfx card
Here the result with a XFX GeForce 6800GT AGP 256MB: