When suddenly it's all right and you can - well, just breathe that big sigh of relief?
The computer has now got a brand new hard drive, and I've decided to invest in an online backup service: Just Cloud is backing up everything on my hard drive as I type (it's been a long job but actually painless, as it's doing it in the background). It's also going to back everything up automatically every day, which I won't even need to think about - and (bonus!) I can access everything from any computer or mobile device anywhere in the world.
Now I just need a nice foreign holiday so I can test it out...
Oh, and the ability to remember my password.