I have discovered a near perfect program that allows you to test out any program in a secure sandboxed area without contaminating your registry or Windows folder. Of course it is well known in geek circles (no offence at all) but perhaps people in this forum will find it essential too.
It's Sandboxie from -
http://www.sandboxie.com/index.php?GettingStarted and what it basically does is create a virtual environment simulating Windows but only using the files needed by the program you are installing. It copies into the virtual environment the relevant Registry section - the place where all the crap goes - and any system files needed by the program installer. You can also use it for browsing - and all your browsing downloads and cookies are saved into the mirror image system area.
In practical terms what you see on your PC is a folder called Sandbox. When you have finished testing and browsing and you want to clean up, you delete the entire folder and all the rubbish disappears into the trash and your original folders or registry are not touched at all. Brilliant.
Why is this relevant to this forum? Because you can install programs such as
nPassword in the sandbox and then copy across only the basic program onto your usb drive or whatever. Many of the programs although clean and portable, do install uninstall info and the like, although no dlls or other files that degrade their portability. I copied nPassword onto my usb drive by installing into the sandbox first. I then copied the basic exe file which is all the program actually needs to run, onto my usb drive.
I hope this information also protects other users from the poison of trojans and viruses too.
[Moderator note: signature had spammy links. Removed.]