How to activate optimus graphics in T420s?

I have a T420s with NVS 4200M, but somehow I could not activate the discrete card, as evidenced by the fact that when I play games (PES 2011), the game automatically says that I only have the Intel card + 64mb dedicated memory. I tried these actions, but to no avail:

1. Setting the bios to 'discrete graphics', 'integrated graphics' and 'optimus' respectively.
2. Installing the latest drivers from NVIDIA
3. Installing the latest drivers from Lenovo through system update.

Note that:
1. In my T410s there is the option to choose 'high performance' and 'low performance' graphics in the Power Manager, where such an option does not exist in my T420s.
2. The Power Manager sometimes shows up not working/ crashed on startup.
3. There is no switch button in the 'NVIDIA Control Panel' and 'Graphics Options' assessed through right-clicking the desktop.
4. The NVIDIA card is found to be present on Device Managers.
5. My system specs include i5 processor, 8gb ram, intel 310 80gb, 320gb stock hard driver and ultrabay battery. WEI shows 5.6 on graphics and 6.5 on gaming graphics.

Would really appreciate any assistance regarding the issue. Thanks in advance!

 

In order to use Optimus properly, you MUST set the BIOS to NVIDIA Optimus and install the video package that includes both the Intel and NVIDIA video drivers.

The current package is at NVIDIA NVS 4200M, Quadro 1000M, Quadro 2000M (Optimus) Display Driver for Windows 7 (64-bit) - ThinkPad for 64 bit.

The current package is at NVIDIA NVS 4200M, Quadro 1000M, Quadro 2000M (Optimus) Display Driver for Windows 7 (32-bit) - ThinkPad for 32 bit.

 

I just got a T420 yesterday and I've been trying to figure out how effective the optimus graphics are.

In the NVIDIA Control Panel I found controls for global settings and individual program settings which seems to allow for a manual override on the utilized graphics source.

I've been pleased with the performance of the computer, but I have been monitoring heat in the cpu cores and gpu and they both reach 80+ celsius within 5-10 minutes in a 3D game, even with the Lenovo TurboBoost+ activated.

Have you had any issues with heat?

edit: I re-read your thread and see you've found the NVIDIA Control Panel. To be more specific, I found the tab in the "3D Settings --> Manage 3D Settings" tree.

 

Thanks! Never knew that it was so obscure.... + rep!