I have an ATI HD 2600 pro and a Nvidia 6600 GT, and a 22" LCD DVI on the ATI and a 14" CRT VGA on the Nvidia. They were both working fine until I downloaded and installed the newest drivers(9.2) for the 2600 pro. When I restarted my computer, my second monitor didn't work anymore. In display properties, when I click the settings tab I get a message box that titled Invalid Display Settings and says: "The currently selected graphics display driver can not be used. It was written for a previous version of Windows, and is no longer compatible with this version of Windows. The system has been started using the default VGA driver. Please contact your hardware manufacturer to get an upgraded driver, or select one of the Microsoft provided drivers." Now only the ATI driven monitor are in the settings, and my second monitor dissappears. The device manager says there are no problems with either monitor, or display adapters. I reinstalled the old ATI driver, updated the Nvidia driver, uninstalled and reinstalled the Nvidia driver. All of which did nothing. The catalyst control center is able to see the other monitor as well, but it can't enable it. I did notice something weird, that is that in msinfo32 the driver and cards get confused, the dll files, display settings, and the RAM amount are switched, but the driver path is correct: Name NVIDIA GeForce 6600 GT PNP Device ID PCI\VEN_10DE&DEV_0140&SUBSYS_00000000&REV_A2\4&7ABB47A&1&0068 Adapter Type ATI Radeon Graphics Processor (0x9589), NVIDIA compatible Adapter Description NVIDIA GeForce 6600 GT Adapter RAM 512.00 MB (536,870,912 bytes) Installed Drivers ati2dvag.dll Driver Version 18.104.22.16808 INF File oem1.inf (nv4_NV3x section) Color Planes 1 Color Table Entries 4294967296 Resolution 1680 x 1050 x 60 hertz Bits/Pixel 32 Memory Address 0xCC000000-0xCFFFFFFF Memory Address 0xC0000000-0xC7FFFFFF Memory Address 0xCB000000-0xCBFFFFFF IRQ Channel IRQ 19 Driver c:\windows\system32\drivers\nv4_mini.sys (22.214.171.12408, 6.02 MB (6,308,224 bytes), 9/22/2007 12:47 PM) Name ATI Radeon HD 2600 PRO PNP Device ID PCI\VEN_1002&DEV_9589&SUBSYS_200217AF&REV_00\4&243D7BD0&1&0070 Adapter Type GeForce 6600 GT, ATI Technologies Inc. compatible Adapter Description ATI Radeon HD 2600 PRO Adapter RAM 128.00 MB (134,217,728 bytes) Installed Drivers nv4_disp.dll Driver Version 126.96.36.19912 INF File oem4.inf (ati2mtag_RV630 section) Color Planes Not Available Color Table Entries Not Available Resolution Not Available Bits/Pixel Not Available Memory Address 0xB0000000-0xBFFFFFFF Memory Address 0xD1000000-0xD100FFFF I/O Port 0x0000A000-0x0000AFFF IRQ Channel IRQ 18 I/O Port 0x000003B0-0x000003BB I/O Port 0x000003C0-0x000003DF Memory Address 0xA0000-0xBFFFF Driver c:\windows\system32\drivers\ati2mtag.sys (188.8.131.5212, 3.33 MB (3,488,768 bytes), 9/22/2007 12:47 PM) How can I get my second vid card working again?