You could create a new windows user account and see if running PS from there helps.
You really have a low amount of ram. Increasing the amount would improve performance. 8-32 GB depending on what you can afford.
Ram is easily replaced by the user, no tech repair needed.
Thanks, I'll give it a try later today and let you know how I fare.
It's odd how the same software used to run without any hitches previously, though in saying that, I recently had my laptop screen replaced at a PC repair shop, so I'm now wondering if they've tinkered with other things. I didn't make a note of my system specs before having it replaced so I can't compare. I know this is off topic, and sorry if this sounds silly, but is there a way to find out previous system specs if indeed something has been altered?
You can check your computer's user guide or go online and google search your particular model.
If you suspect anything had been placed on your hard drive like malware, go the bleepingcomputer.com and go to the "Am I Infected" forum.
A volunteer will ask you to download diagnostic software, run it, and paste the results back into the forum so they may have a look at it. It's all free, but you need to follow through and have patience.