If you are concerned with security on a windows box with regards your account, run it as a normal user with no rights to do anything.
Then when you do need to install, you can elevate your privileges by shift-right-clicking on the EXE or whatever in question, and selecting "Run as different user" from the popup menu. You get a logon prompt, put in the login credentials, and that process
only can run with the rights required to install.
After that ensure patching is up to date and the whole thing is behind a properly secured firewall, or failing that a well configured router. Then it's just down to the chair-to-keyboard interface problem
cheers,