Can you have two versions of toolkit be installed on windows?

Can you have two versions of toolkit be installed on windows? And to switch them easely in visaulc? I want to try new one, but do not want to uninsall current version.

At least for the most recent toolkits (3.2, 4.0), you can have two versions of them installed on windows.
I installed both 3.2 and 4.0, and they go in separate directories. The Installer seems to add an environment variable ‘CUDA_PATH_V_’ for each installed toolkit.
Take care when using the variables ‘CUDA_PATH’, ‘CUDA_BIN_PATH’, ‘CUDA_INC_PATH’, ‘CUDA_LIB_PAH’ as they seem to refer to the last installed toolkit.

Switching between them in Visual Studio might work by changing these environment variables properlay before launching visual studio so that they refer to the toolkit you currently want to link against.
When using CMAKE for generating the VS project files, there is an easier way, you just have to change enviornment variable ‘CUDA_BIN_PATH’ to the proper directory and then call ‘find_package(CUDA)’. Note within CMAKE you can also change enviornment variables, e.g. “set (ENV{CUDA_BIN_PATH} $ENV{CUDA_PATH_V3_2}/bin”).
Another advantage of using CMAKE is that it’s also quite easy to generate 32-bit and 64-bit version of a library.