that's probably because you literally copied the install directory from one drive to another. apache and mysql are both installed as services, so this would mess both of them up. like I said before, I've absolutely no experience with "WAMP," but I'm not surprised in the least that what you did made it not work. a general rule of thumb is that if you install a program, you probably can't just take its directory and copy it where ever you'd like and expect it to run correctly from there. registry entries are made that hold reference to where these applications were installed as well, and this may or may not stop the application from running correctly.

if you just installed it on the other drive, I'm sure it would run just fine.