ATI card works fine in Win7 Ult RC, not in Win7 Prof

[jrem]

I've been using the Windows 7 Ultimate release candidate as an evaluation copy for a while now with no problems. I have an ATI radeon mobility X1600 graphics card in my laptop and I'm using an external monitor through my laptop's DVI port. I bought a product key for Windows 7 professional and therefore had to reinstall that version because I'm using Ultimate as the evaluation copy. I have each version on its own partition so I can switch back and forth between the two.

The problem is that the newly installed windows professional copy will not recognize my ATI graphics card and I can't use my external monitor. It has the standard windows VGA adapter drivers installed. I've installed and run the ATI file i downloaded off their site, '9-9_beta_win7_32_dd_CC', and this accomplishes nothing. I looked in device manager on the working ultimate version and the card is installed correctly so I copied all of the drivers and files it says its using and then tried to update the driver for the standard windows VGA adapter and it says it can't find any better drivers than the current ones.

I remember initially having this same problem when I first installed the Win7 Ultimate RC several months ago but I have no clue how I was able to get it to work... Any ideas?

 

[kegobeer]

There's a thread on the MS social forum about the X1600. Have you read it?

I need working driver for my ati radeon x1600 (windows 7)