Is it possible to run a GTX260 & 8800GT together on 1 Windows XP-Pro 64-Bit System & what setting Changes do I need to make if any to get the BOINC Manager to recognize both cards.

Right now only the GTX260 is being recognized when the BOINC Manager starts up & only 1 GPU Wu is being run ???

I ran a 280 with a 9800 GT and the 280 with a 295 with no problems ...

first caveat, I was running XP Pro 32-bit ...

But, I think the key may be that you do not have the drivers installed for one of the cards. In some instances I had to specifically tap the card and install the driver for it. That would be the first thing that I would check that each of the cards has the up-to-date driver installed.

Some have reported that you have to extend the windows desktop to both cards ... that would be the other thing I would look to ...