Install MSI as another user

You may know that with Microsoft’s inclusion of User Account Control, starting from Windows Vista, you need to “elevate” your permissions so that you can do system wide actions that make changes. This simply means that for most tasks, like installing software, you need to open the installer with “Run as Administrator”. This is true even if you are logged on as the user named “Administrator” (you will probably have found out by now that if you are logged on as a user who is Administrator or a member of the local Administrator’s group, that you actually have less rights than if you were logged on as a regular user). Somehow, you need to not just “Run As”, but “Install as Admin”.

So, to install software you need to right-click on the icon and choose to “Run as Administrator”, or even hold shift when right-clicking “Run as different user” and then enter an administrative user (which can’t be the one you are logged on as… see above). However, this “Install as Administrator” option is not available for MSI files (Microsoft Installer).

How do you install MSI files as an Administrator?

The normal answer from Microsoft is that you should open a command prompt as Administrator, and then type in the command line for running the MSI as Administrator. Not exactly quick and easy. Wouldn’t it be better if you could “Install As Admin” in the same way as you can “Run As”?

I have written this little .REG file that when you run it, it will put in an option for “Install As Admin” for MSI files.

Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\Msi.Package\shell\Runas]
@="Install &as Admin"
[HKEY_CLASSES_ROOT\Msi.Package\shell\Runas\Command]
@="msiexec /i \"%1\""

Copy all the above, save it in plain text as a .REG file.