Yes, but only if you are logged on as an administrator of your system. If you are not, your OS will not let you do the following. (But try anyway.)
Log on as an administrator if you need to, or ask for help if you don't know what this means.
To edit the PATH variable, you will need to find Control Panel on your system:
Once you have found it, click on "System" (usually a little computer icon).
In "System Properties" click the "Advanced Tab" and then click the "Environment Variables" button:
Is PATH an Environment Variable?