More PC problems, but I sorted them with some lateral thinking!
State of play was this: I had an unformatted D drive that was failing to show up on windows.
I had XP installed on my C drive, but something was wrong. On startup an error message would pop up telling me that svchost.exe was buggered. This caused my computer not to see it's soundcard, and to replace it's XP style toolbars with flat, windows 98 style toolbars. The lack of soundcard was having knock-on effects on certain applications. But did I cry? Did I curl up into a little foetal ball and cet like a girl? Did I take the piss in a really shallow and obvious way like Frankie Boyle? No! I rolled up my mental sleeves and investigated the situation!
svchost.exe is a complicated subsystem of windows that contains all sorts of bits and pieces essential to the smooth running of my computer. But I found the event viewer, and isolated the cause as being a file called "qmgr.dll".
I looked for this file in my windows XP disk, but I couldn't find it. And then, here's the clever bit.
I formatted the D drive, and installed XP on it. Then I found the D drive installation's version of qmgr.dll, and I copied it and pasted it into my C drive installation.
And it worked. Now my proper C installation is working properly again.
Which is lucky really, because I wasn't that clever. I forgot to make a back-up copy of the original qmgr.dll file, so if it hadn't worked, I'd have been knackered.
But anyway, there you go. I'm proud of myself for this one, because it goes beyond what I thought I was capable of dealing with. I shall keep my D drive installation of windows as it is, and if I have any further problems, I have a ready made repository of uncorrupted files.