Ed,
From the "All settings" menu in the action center, type "Environment" in the "Find a setting" box. It should give you an option called "Edit environment variables for your account". It will open a new window and you will see the two variables for TEMP and TMP. Alternately, from the older Control Panel, you can open "User Accounts" and you should see a link on the left of that window for "Change my environment variables". Hope that helps.
-JD
