For PhpED to start and work properly you need to login with the same user account which will be using PhpED. If this account has administrative privileges you can simply run the installer, otherwise you should use Run As and select user account with administrative privileges, which is usually the Administrator.
If you installed as Administrator and are trying to run as a different user, you may get an error because from the software point of you these two users are different. PhpED license does allow for multiple installations on different machines, but it should be one user of the software only. Please contact our sales at sales@nusphere.com if you need additional licenses of PhpED. Thank you very much!