Thanks again for all of the feedback. I've noticed a few other issues with my ol' desktop the last couple of weeks, which confirmed to me that trying to upgrade might be more hassle than it's worth. So I decided to bite the bullet and splash out on a decent spec new PC that should last me a good few years without needing major upgrading. I appreciate that I haven't jumped on a great sale price or anything, but I had been given a window to treat myself for a birthday gift so took the plunge and thought it was decent value overall. The reality is that it will be wildly over-spec for me (I'm never going to find the time to do any hardcore gaming).

https://www.pbtech.co.nz/product/WKSGGPC50370/GGPC-AMD-Radeon-RX-9060-XT-16GB-Gaming-PC-AMD-Ryze