First of all, System Environment Variables defined under NT are the same no matter who is logged on at the computer. When you are logged on as a member of the Administrator group, you can change values or add new variables.

Right-click My Computer and select Properties, then click the Environment tab. Here's where you can add items or make changes to your NT environment. For instance, let's say you want to add a folder to your PATH statement. To add or change and environment variable, click its name in the System Variables list or type a name in the Variable box (in this case, PATH), type or change the value in the Value box, then click Set.

Whenever making changes to the PATH statement, just make sure the NT system path comes first (%SystemRoot%\system32). Additional values must be separated by a semi-colon.