I have, however, recently resolved the problem - and the solution is a little embarrassing - but I'll share it here for the benefit of anyone else with the same issue.
Quite simply, one of the function keys on the laptop has a 'switch the mouse pointer on or off' feature. This is something I have never seen before, despite having used laptops since they were practically first available.
On my particular laptop (Toshiba Satellite L855) the F5 key does this. It has a picture which is hardly identifiable as a mouse with a line through it.
Press this (or press FN+F5 depending on you configuration), and hey presto... the cursor returns.
Thanks again - and hope this helps someone else.
1140 people were helped by this reply
Did this solve your problem?
Sorry this didn't help.
Great! Thanks for marking this as the answer.
How satisfied are you with this reply?
Thanks for your feedback, it helps us improve the site.