Different users for different tasks, Your thoughts, please

I'm currently awaiting parts for my new HTPC. It will be used as my main computer. The computer I'm using now will be turned into a file server for the network.

My question is regarding my main HTPC. I've noticed over the years that many applications ask you if you want the software available to each user, or only selected ones. I think the intent is to keep 'users' (aka wife and children) from accidentally using software that could change how the computer works.

I think this could be used in a different way. For example, if I want to play the latest and greatest video game on the HTPC, I don't want my printer drivers, anti-virus, Java RTE, web-cam, etc wasting resources.

I would probably use a few 'users' such as Media, Gaming, Web, Disk Authoring.

Has anyone tried this, or know of any limitations/issues this use would have?

Would there be any point? I mean a modern computer isn't lacking in resources. Most CPUs idle and memory limitations are rarely reached, especially on an HTPC which really only does media playback.

The idea behind multiple users is to allow people to share a computer, but have some degree or personalization. If you installed an app that only you need, maybe for work, you wouldn't need to make it available to other users of that system. It doesn't have much to do with resource management.

My children a hard time not visiting virus laden web sites. I finally created a new user called watch movies. then promptly changed my admin password. I restricted all programs including printing. all anyone can do on watch movies is watch movies. no internet, no nothing. since then I had no virus.