There is a .reg file in the archive if you downloaded the game from here. If there is not, then download the game from here.
If you can't see the files extention (which I never understood why, it's one of the most basic things to see in Windows), there is an option in your folder options to enable you to see all extentions. By default, this stupid option is turned off.
If you don't have the admin rights on your computer, then talk to your sysop.