Hi all. I have a T420 and wiped it clean for my own Win 7 64-bit installation. While running the driver updates from Lenovo's driver site, I noticed separate drivers for the nvidia card - looks like the "regular" drivers and the optimus separately. I didn't install from there. Instead I went to nvidia's site, like I always do, and installed the latest driver for the NVS 4200M. As a side note, my system also has an integrated Intel card. All seems to be good so far, but haven't tried any 3d apps.
I assume the new driver has Optimus included in it? I have an icon that shows Nvidia GPU activity, which is really cool. Lets me determine what 3d programs use the Nvidia GPU.
Am I all set or do I need to make any BIOS changes? I just don't want my Intel card to start working in the middle of a 3d app, yet I don't need the nvidia card working while in 2d.