What version of IE are you using? In each of the more recent ones, there’s a setting under “internet options” that forces links to be opened in new windows or tabs.
I have tabbed browsing switched off but there’s an option in internet options->advanced called ‘reuse windows for launching shortcuts’ I switched that off to achieve what I was looking for.
Thanks for pointing me in that direction
I did look there first, but because of the way it’s worded I must have missed it. I guess I was looking for a checkbox for ‘open links in new window’.