Can't uninstall to return to vanilla Options

[Joe3983]

I'm trying to uninstall Shockwave to return to vanilla so I can edit some of the .big files myself. After multiple attempts, I keep getting the same error: when I try to launch GZH the screen is purple with only boxes and no animations or anything. Going into options, the game version still shows Shockwave 1.1 at the bottom with the zero hour 1.4. I've tried reinstalls, deleting all the folders manually, uninstalling everything and cleaning the registry, and I have no idea how many reboots.