[entwisi]

In which case the "password" is of even less use as all trojans/viruses/ etc would be running as the logged in user(your router provides a level of indirection to stop direct access to your machine ). I'd have been more impressed if you said he'd set up a limited privilage user account for your day to day use and an Admin account for the days you want to install anything etc. This way any trojans/viruses would also need to have privilage escalation functionality to do any real damage(which most dont as Windows accounts are by default admin privilage level so they dont need to worry about it).

Also hacking URLS like logmein/advert serving URLS in the local hosts file to direct to localhost is a very useful and yet basic level of security that most people dont use.