Ok, so recently I have reorganized my PC, reinstalled, and configured most everything back to how I like it. I partitioned my Windows drive into two, one for Windows, and the other for ppics, music, videos, storage basicly. I only alotted 20G's for Windows and all it's parts and have HL2 installed on the same partition, along wiht a bunch of my programs. I want to move most of my program files over to the data partition, and run them from there, so that if Windows does somehow get a virus I can contain it and not have it effect on programs, and has less places to go. Now, I now some programs make an entry into the registry, and some will not function if they are moved. I moved a couple to try it out, and they run fine. What would keep a program from running if it is moved, as long as I change where it is looked for?