Henry and Gemma...
Thanks for the replies - would have thanked you sooner but forgot altogether that I had started this thread....
Gemma - can't download anything....Company issued machine, no admin rights, but I've had a look at Jetcleaner and will probably put it on to my own machine next time I'm back in Europe..
Henry - Thanks for the link....Seems I shouldn't be too worried, then....And no, these are .dat files which I can't open to edit....
But the reason for coming back to reopen the thread - just noticed that I now have a few other cookies which won't delete, and which reminded me....Including the @pprune.org cookie, so I assume that this is probably a Windows or, perhaps, even an Adobe problem rather than anything malicious....
I even tried this - emptied and then deleted the caches, but these stickies are still sticking....
Temporary Internet Files Folder location in Windows 7 | 8