BTW, what does configuring have to do with the fact that they both leave traces of crap all over your system if you ever decide to uninstall them?

I've yet to have that problem, mainly because I setup a system to monitor and log any changes during the installation of software, changes and locations in the registry and so on. Three to Four mouse clicks and a system is totally cleaned of anything installed which I want removed.

As implied previously, if a system is configured correctly, it is not going to have a problem with email attachments, program removal, installation, configuration or stability. But it has to be configured or everything Windows leaves crap on a system without question. Orphaned files are quite common and something that should be scanned for and removed periodically.