Can one reinstall apps from windows.old?

After freaking out and losing my mind over the past three days I am still trying to restore my files. However, I’ve hit a snag. My user contents have been successfully restored without any problems. I wondered if I could just do the thing with the Program Files, and Program Files (x86) folders. Somehow I don’t have permission to do that now. That concerns me regarding a particular game I play named Garry’s Mod, wherein I can place unofficial scripts in the game folder and they will run as legacy add-ons. Useful for alpha testing or unfinished mods, or mods that happen to have the same name as an existing mod on the Steam Workshop. Or for just brute-forcing your way through understanding Lua scripting, which is confusing as all hell. Is it possible to restore the files from the two folders I mentioned earlier, or am I forced to start over? Or can I restore the files if I redownload the programs themselves?

Edit: Never mind. I am dumb. I can’t drag the folder itself over, but I can drag the folders inside the Program Files folder over.