Code 38 when trying to run cppOverload sample

I have Windows 7 64-bit on my machine and GeForce GT550M with 320.57 driver. I installed CUDA 5.5 64-bit for Windows 7 and tried the samples, and got the error: code 38 “cudaGetDeviceCount<&deviceCount>”

Anyone knows how should I fix the problem?

Hey guys I figured it out… I didn’t turn on the switch on my laptop so the system can’t switch between the two graphic cards… It’s working properly now