Problem solved!

I turned off the new modern/router and then tried to close the computer down and it closed immediately... no problems!

It's like .... der! Why didn't I think of that?

So thank you Dejibo, Jo*Mar and mrsD for your replies. I truly appreciate your assistance, but it looks like my new hardware is definitely to blame.

For future record, my laptop was new in September 08. It runs Vista and I use Firefox as my main search engine. The new modern/router is similar to the one pictured below.

Anyway, before I found that switching off the router would allow me to shut the computer down, I had no trouble closing any of the programs that were open, and when I went into the task manager, there are no applications open at all after I've clicked shut down.

Naturally there were processes happening but I wouldn't touch anything in there. Me going into that area would be akin to a bull in a china shop, as most of those are exe. files and if I hit something I shouldn't, I'm likely to crash the whole thing.

Now that I know I have to turn off the router/modern whenever I want to shut down my laptop, is the frequent switching off likely to cause any future problems for that? I only ask because I've been through a couple of other moderns (wired, one computer access type) and was told only to turn those off if absolutely necessary.
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