This installation is forbidden by system policy. Contact your system administrator

After much searching I found this solution that worked

start > run > regedit

Browse the registry to HKLM\Software\Policies\Microsoft\Windows\Installer

Create: DisableMSI       Type: REG_DWORD  value = 0  

 (0 should allow you to install it was originally 1) 

(In my case the value had been set to 2 so I changed it to 0)

I hope this helps someone too..