So you followed the steps...
Here (9700 pro instructions...works the same for the 9500 pro, just different filenames for the bios)
Here's the original thread from Warp11 himself...TONS of info for those who need help
And
here is Warp11's homepage, in case you don't have it...more info there as well.
What are your hardware specs? AMD or Intel box?
So...you made a bootable floppy disk...used the ATI flash utility and
backed up the original bios...then flashed it with the warp11 bios...correct? Did you flash it with the correct bios...there's quite a few variations and it can be confusing which one.
...then you rebooted...and you can see the bios screen...and you can see that you're booting into Windows...that means you
didn't hose the card...if you did, you wouldn't have any video at all. I'm not sure that if you flashed it with the wrong Warp11 bios...say the 9500 instead of the 9500pro bios...if that would still give you video or not...probably would get a checksum error instead and it wouldn't flash at all.
Are you using the bundled Sapphire drivers or the Catalyst drivers? You have to use the Catalyst drivers. Did you go into safe mode...uninstall anything related to Sapphire or ATI drivers...then reboot? Chances are, since you have video, your card is fine...there's something that Window's isn't happy with. Are you running PowerStrip by any chance? If you are, get rid of it, at least on my machine, it would lock it up once I flashed the card. Use the
Rage3D overclocking tools instead like Rage3D tweak or Radeonator.
Do you have any other utilities installed relating to video...like any tweaking or overclocking utilities...remove them.
If you did back up the original bios...you could flash it back to see if that fixes it. If you didn't back it up, you can probably find the original bios in the links I gave you above.
Do you have another machine you can throw the card into to test it?
I bit the bullet and did the bios mod on my Sapphire Atlantis also...I knew there was a chance that I could hose it...but couldn't resist the urge to do it. Before I did anything though, I completely removed any drivers and anything related to ATI or Sapphire...then I rebooted and proceeded to flash the card and rebooted...when I got to Windows XP, it detected it as a new 9700 pro and I installed the Catalyst drivers...and all was fine. I hope yours will be too.
Like I said, I doubt the card is hosed since you have a display...good luck! Let us know what happens!!