Saves you having to redownload the game over and over. It will detect files already present, verify them, then basically say 'Hey, you already have this installed.' Then copy your copy, paste it into the Steam folder above. This will remove any trace tidbits of the mod leftover. Then go and delete the VTMB folder from inside your Steam folder. When you're done, tell Steam to uninstall the game.
Install the mod you want to try as per its instructions to the VtMB inside your Steam folder. Keep that copy to the side as a clean install. Place that copy somewhere OUTSIDE the x86 folder.
You need to go to C:Program Files(x86)/Steam/steamapps/common and copy the Vampire the Masquerade - Bloodlines folder from there. They also all change the game so much, it would likely not even work if you tried to run them all at once. They all have older versions of the UP built into them so installing UP 9.4 will cause problems.
The big mods like Companion, Camarilla Edition, Final Nights, Antitribu, Unofficial Patch, and Clan Quest DO NOT operate together.
