Preventing app installs

We recently purchased Secure Lockdown v2 - IE Edition Build 2.00.181
and have it running on Windows 10 Enterprise Edition 64-bit ver 1703 (OS Build 15063.608)
We've found that even with the No App Install option ticked, it still allows executables to be downloaded and installed.

For instance, we've been able to install
Chrome
Firefox
NCH Debut Video Capture software
Jam Software's TreeSize

These were just examples found during our testing. Obviously there are others, and potentially malicious ones, so how do we prevent that from happening?

I've read the recent post from Joe Y "running of programs" which makes mention of a similar case, and I can confirm that none of these programs were previously installed.

We have the option No Downloads unticked in order to allow PDFs to open, for both general web browsing and
for an internal staff payroll program. Acrobat PDF Reader is the only other software installed.

We prefer not to limit the sites that users have access to if we can help it.

The key for us is to allow PDFs to open, but to prevent all possible programs and apps from being installed. Have we missed something in the setup?

Thanks
Dom

None of the programs that were downloaded use the Windows MSI method of installation. This is what the "No App Install" option blocks. To prevent the installation of the programs mentioned, you need to block downloads altogether. Note that if there is a PDF viewer addon for IE then a download shouldn't be needed.

Ok, thanks for the reply, much appreciated, we'll investigate further into the No Downloads option and see if we can get a PDF addon solution to work for us.