Everything is working properly again now, except that I am unable to connect wirelessly to the internet via my Belkin router.
I have just had a lengthy conversation with a nice chap from Belkin who did all he could to help me, but his ultimate verdict was that I need to reinstall the LAN card via the "motherboard CD" I got from Dell when I got my laptop.
The thing is, I have no CD that says it's a motherboard CD. And I bought this laptop more than five years ago - Dell are hardly going to send me anything I might need now.
Can anyone here tell me if I'll be able to connect wirelessly again, as I was doing before the recent problems on my computer?