Dumb question? Are average users Admins?

This may seem like a dumb question, but I've been a software engineer for 20 years and all my software has either been for geeky, technical users, or for use in a corporate environment where other people deployed it for me.

Now I'm writing an app for ordinary, not technical, non-geeky users on their own PC's (XP and Vista). The app is written in C# using VS 2008 and needs to be deployed with .NET 3.5 . The MSDN .NET Framework 3.5 Deployment Guide for Application Developers says that Administrator privileges are required to install the .NET Framework version 3.5. I'm planning to distribute the .Net framework in my deployment package to be installed automatically (if needed) when they install the app.

Is the average mom&pop user who bought his or her PC at Dell or Best Buy or Walmart running in an Administrator account? What's the usual protocol when deploying to normal, non-geeky end users?

Thanks in advance.

Yes, for installers. The app itself should work when run as a normal user if at all possible, but the installer of course will need to be run as an administrator in order to write to Program Files, edit the registry, register dependencies, etc.

If they can install Windows Updates. Might want to have them test it out that way. I've seen virus infected machines that have never been updated... Administrator Account disabled and things like that.

Then, there's CLICK-ONCE

Which installs while you're online, reads your ROOT folder and displays the content. It won't run when the site isn't online, and checks for updates when it runs