I moved my PC into a different room over the weekend. I disconnected and reconnected all of the cables etc. and it seemed to be running fine. I most often use the PC for multitrack recording and soon came to realise that I couldn't record any sound through the line-in or mic sockets on the soundcard. Tried different cables and different audio sources but absolutely no sound was getting through. I tried all sorts of tweaks and eventually uninstalled/reinstalled the soundcard and associated programs, but still no joy. Frustrated, I turned to the manual and, slowly, the lights came on inside my head. Now, I thought I was "reasonably" competent when it came to sound on a PC but I had managed to put the cables into the soundcard in the reverse order! (Line-in into line-out etc.) So if anyone can point me into the direction of a memory booster, feel free to do so ;O)
Moral of the story is: Before doing something major & tearing your hair out - check the simple and obvious things first!