You want want's called a sandbox.
First, anything that can write to the C disk can get to the OS and other critical files which would cross-infect the normal windows session.
Second, a user account (without admin privileges) is a bit like what you seek but its not the strong sandbox that you need.
1. Virtualization would let you run multiple OSes but would require you to install software. (Can you boot from a USB drive?)
2. What about remote screen sharing with an off-site PC that can do all the things you seek?