I want to transfer the steam app from my pc to HD, then to another pc. is it possible since my profile is saved to it?
Here's the problem: when you're installing any program, it automatically has to make several changes to your registry. This is the same with Steam. Among these are an InstallPath, a Language, a SteamPID and others. The InstallPath and Language could in theory be entered manually. However, the SteamPID is a unique key that's different from computer to computer. I have 3 machines with Steam installed on them, and all 3 of them has a different SPID. I even think that, were I to reinstall Steam on one of them (which I'm currently doing), I'd get a different PID.
In addition, when you start Steam on a new machine for the first time, you need to connect to the Steam servers to log in. You literally CANNOT log in or start a game on your computer without first authenticating with the live servers.