W7 And ThinkPad T400 ATI Radeon 3400 Series Driver

I have a T400 which has the following two display adapters:

ATI Mobility Radeon HD 3400 Series

Mobile Intel(R) 45 Express Chipset Family

After installing Windows 7 and checking device manager, the ATI adapter does show up under the "Display adapters' section, but it has a ! sign on it, and if I click for details, it says:

This device cannot start. (Code 10)

I tried downoading and installing this:

Lenovo Support & downloads - ThinkPad Switchable Graphics Driver for Windows Vista 32bit and 64bit - ThinkPad T400, R400, T500, W500

and when I rebooted, it went through some diagnostic tests in a cmd window to finish installation. But when I checked the device manager again, the ATI adapter still says it cannot start.

I also tried this:

ATI Catalystâ„¢ Mobility Display Driver

which I got to by selecting Windows 7 32-bit > Mobility Radeon > Mobility Radeon HD 3000 series.

It seemed to install OK, but I got a message which I've gotten with previous attempts, which says:

"The Catalyst Control Center is not supported by the driver version of your enambled graphics adapter. Please update your ATI graphics driver, or enable your ATI adapter using the Displays manager."

I went to the device manager, right-clicked on the ATI adapter and did Update Driver, and it did at first find a better match but said it couldn't be installed with the same error message from above (Code 10). Now, when I try to update the driver again, it says the best driver software is already installed.

Any ideas to fix this?