Regedit or other programs won't open

Hi, I am having a rediculouse problem!

Today i was trying to install a game on my pc but it was installing in a location i didn't want it, so i went into regedit/HKEY_LOCAL_MACHINE\ SOFTWARE\ Microsoft\ Windows\ CurrentVersion and changed all the files in there to a different drive (From E:\ to C:\ ), now no programs open, and i can't open regedit either to change it, so confused, to reinstalling windows is a last resort.
NOTE: Programs like spotify and google chrome (if opened directly) do work.
help would be appreciated

thanks