Completely lock a computer and force it to use a single application

Solution 1:

The common term is to make it into a kiosk style machine.

Then you can find a few guides via a search engine.

I found this guide that looks promising, uses local group policy to restrict applications being launched, that combined with your application starting up on initial log in sound like a good start

• http://sbs.seandaniel.com/2010/01/how-to-lock-down-windows-7-kiosk-or.html

More links

• http://support.microsoft.com/kb/555463
• http://helpdeskgeek.com/how-to/how-to-setup-windows-vista-and-7-as-a-kiosk/
• http://midspot.wordpress.com/2006/10/26/how-to-create-an-internet-kiosk-in-10-easy-steps/