Cant install Offline Updater

I have installed CESM 1.6 and CIS 4.x in 20 Endpoints.

I also wanted to install Offline Updater, but I keep getting this message:
The system administrator has set policies to prevent this installation

The OS is Windows 7, 32bit.
I have googled it but the solutions I found dont work with Win 7.
Most of the solutions state that the problem is Windows Installer.
But I can install many other products, including CESM.

Does anyone have any idea how could I solve this issue?