Precision T5500 Issue With nVidia Display Driver

O.S. = Windows 7 (64-bit)

Recently hooked up a Dell Precision T5500 to a Dell u2410 monitor and noticed that the generic PNP video driver didn't support the resolution that I wanted (1920x1200). I went to the support.dell website and downloaded the recommended driver for the system (r317691) nVidia 275.89. After installing the driver and rebooting the system it gets caught in a "log on loop". I can get the computer to boot up and get to the windows log on screen, but after I enter my password it reboots and doesn't run Windows.Then this sequence repeats. I ran just fine before this driver was installed.

This issue occurs no matter what input/output I use (VGA, DVI or DisplayPort).

Thanks for any info

Craig