Question: I have problem running samples provided by Nvidia in their GPU Computing SDK (there's a library of compiled sample codes).

For cuda I get message "No CUDA-capable device is detected", for OpenCL there's error from function that should find OpenCL capable units.

I have installed all three parts from Nvidia to develop with OpenCL - devdriver for win7 64bit v.301.27, cuda toolkit 4.2.9 and gpu computing sdk 4.2.9. 

I think this might have to do with Optimus technology that reroutes output from Nvidia GPU to Intel to render things (this notebook has also Intel 3000HD accelerator), but in Nvidia control pannel I set to use high performance Nvidia GPU, set power profile to prefer maximum performance and for PhysX I changed from automatic selection to Nvidia processor again. Nothing has changed though, those samples won't run (not even those targeted for GF8000 cards).

I would like to play somewhat with OpenCL and see what it is capable of but without ability to test things it's useless. I have found some info about this on forums, but it was mostly about linux users where you need Bumblebee to access Nvidia GPU. There's no such problem on Windows however, drivers are better and so you can access it without dark magic (or I thought so until I found this problem).

Answer: 
Ok this has proven to be totally crazy solution. I was thinking if something isn't hooking between the hardware and application and only thing that came to my mind was AV software. I'm using Comodo with sandbox and Defense+ on and after turning them off I could run all those samples. What's more, only Defense+ needs to be turned off.

Now I just think about how much apps could have been blocked from accessing that GPU..
That's most likely because of the architecture of Optimus. So I'd suggest you to read  [NVIDIA CUDA Developer Guide for NVIDIA Optimus Platforms](http://developer.download.nvidia.com/compute/cuda/docs/CUDA_Developer_Guide_for_Optimus_Platforms.pdf), especially the section "Querying for a CUDA Device" which addresses this issue, I believe.