Leading 'feed' on RSS-Feed URL

On some computers registering for RSS Feed seems to work for https://www.insights-crm.com/index.php/blog/ but on one we have noticed that the expected URL https://www.insights-crm.com/index.php/feed/ comes out as feed://https://www.insights-crm.com/index.php/feed/

From Outlook it seems as if the RSS feed is generally working OK, except on the affected computer.

I have spent two days trying to find what is causing the extra “feed://” at the front. Can anyone help or point me in the right direction, please?

Thanks
Ken