I had the same issue and found the answer here.
The problem is that the bat uses de reg command and it searches that in the PATH system variable. Somehow you have managed to get “C:\Windows\System32” out of the PATH variable, so just go to the system variables (right click “My Computer” > “Properties” > advanced config > “Environment Variables”, search the PATH variable and add at the end separated by “;” : C:\Windows\System32