this application is blocked by group policy

Hello,

I don't like Chrome shutting out third party extensions, and the huge dumbing-down that is coming for Firefox, so would like to install Opera and Pale Moon.
I am running 64 bit win7 ultimate on an i7 machine.

Trying to install Opera from any folder on the computer gives this error message

http://www.imagebam.com/image/0f68a8313457985

Attempts to install Pale Moon offline installer from any folder gives this error message

http://www.imagebam.com/image/9fa333313457656

There are no applocker rules.
There are no software restriction policies or software settings.

Attempts to install Pale Moon using the web installer from any folder, as an adminstrator, gives rise to this error message

http://www.imagebam.com/image/24bb77313458861
Note; as mentioned above, I am running 64 bit win7 ultimate on an i7 machine.

Has anyone any idea how to make it possible to install these softwares? Other apps I have installed have not met with this kind of problem. It's almost as if *something* on the machine doesn't want another browser installed.

LATER EDIT; CAN'T SEEM TO FIX THESE BROKEN LINKS! will post urls