Memory not found Problem with 7 and CUDA

Hi everyone,
I’m trying to install CUDA on a Macbook 13" running Windows 7. I followed the Cuda_C_getting_started_windows pdf, but when I launch deviceQuery.exe, I get a total amount of global memory equal to zero ( same process on Mac OSX gives me a result of 265945088 bytes ), and I’m unable to launch most of the examples.
Someone can help me, please?
Thanks.