@sgunhouse Thank you for your prompt reply.
It's something to do with the software in the CCTV recorder box. Although it's only a year old they say that it needs Internet Explorer, as you know this will be shut down soon.
So, I can download Opera 36 without interfering with my current up to date version and then use that to log in to the CCTV system?

I am running a CCTV app that uses Internet Explorer. When I try to log in using Opera it tells me to use an older version 'Opera 36'. Can I have both the current version of Opera and Opera 36 installed on my pc?