Thankyou for your ideas. I'm sorry but I've been away a lot over the last two days and have been golfing and partying for the rest of the time. What a tough life!
I'll certainly have a look at that defragmenter, thank you, vulcanised.
CrapCleaner removes very little, Spurlash2, as I said above in my detailed report posting. It seems to be use and Defraggler which has been adding the Gbs!
Perhaps you mean which little boxes I have checked for its working; most of the obvious stuff but Madame doesn't like me cleaning things like internet cache and browsing history. I certainly have nothing adventurous ticked. I can't get my hands on the offending laptop at this moment but I'm pretty sure that System Restore will be enabled. I don't understand how you think that this might be affecting things though. I am seeing swings from 40 to most recently 75Gb which virtually amounts to doubling disc usage,after all.
That seems a good idea in any event by my book, ex matelot, Vista has a really bad reputation and I have wondered if the old MS offer of reverting to XP might be a good idea on such a space-limited machine (if it can be done without losing everything) but I hadn't thought of W7.