Re: WinXP SP2 won't start after GeForce FX5500 plugged [SOLVED]
I forgot to mention that my MoBo (BIOS) doesn't allow me to disable the onboard graphic card (isn't great?), it's supposed to do it by itself automatically once it detects the new card. Also, I need to press Ctrl+F1 (once on the BIOS) to see some advanced settings (eventhouh there's already an "Advanced options" -or something like that- on the menu... I learned to love the Gigabyte guys)
Anyway, I solved the problem by going to the (real) Advanced options, and changing the AGP speed to 4X, and the "Initialize graphic card" (or something like that) from PCI to Onboard/AGP. Once WinXP loaded and I installed the drivers (though I wasn't sure this was necessary anymore), I returned and changed back the speed to 8X (though I didn't change back the "initialize" option) and also set the 'aperture' (or something) from 64MB to 128MB (the card has 256MB) and it's working fine.
Hope this helps somebody.