Still got the Internet connection problem, and my service provider can't identify the source or cause !
The only thing they can think of, is that a very recent automatic systems up-date has created an incompatibility issue with my 'dongle', which now around 4 or 5 years old.
Both myself and the service provider have run various diagnostic checks, and no fault can be found with the PC, or with the 'dongle'. The latter is evidently working, to an extent, as it can be re-installed and shows up as installed and working, and, of course, there is 'net access - just not to the 'proper' location. I'm assuming their 'diagnosis' is more or less correct, as, in I.T. terms, this dongle is old stuff.
It's driving me nuts, as I can only get a very slow, and much restricted connection via I.E., and find it impossible to do some tasks, such as check my bank account details, as the system 'times out', being so slow.
The good news is, I've been able to get a much better deal with a free up-grade, which I'm assured will also cure the problem, and it suits me admirably. Monthly use has been exceeding my allowance recently, which has been costing more and more each month, but the 'new' up-grade not only works out around the same as I was originally paying (which they've arranged as a form of compensation), and a lot less than I've actually been paying over the last few months (and cheaper than fibre optic), it is also a lot faster (4G WiFi), and the allowance should have been almost four times that of my present monthly use allowance, but they've actually doubled that too, giving me 6.5 times more than I have been getting.
The only problem is, as it's a Public Holiday here in the UK this weekend, I can't get courier delivery of the new bit of kit until Tuesday.
I think I'll hibernate over the weekend !