Which environment variables should I have?

Seems when I installed my Cuda toolkill all of my environment system variables got messed up. Where can I find out what environment variables I need for CUDA to work? I can’t get nvcc to work in command prompt. The toolkill is installed. I fixed the environment variable for cl.exe and then it told me that nvcc wasn’t able to be run and couldn’t be found. This is after I installed it. Can someone tell me the names of the variables I need and what paths I should be using to get this to work?