Can't help with the freezing Clive, but there are ways of avoiding this situation, this in my way.
ON my desktop PC (XP) which has most of my stuff on, I use Casper to clone my hard drive, this creates a complete copy of the hard drive including the operating system, onto a second hard drive so that if something goes wrong you can just switch off your PC and restart it on the backup drive and it is exactly the same as it was at the time of the last backup, you can be up and running in minutes even after a hard drive fails completely.
http://www.fssdev.com/products/casper/benefits.aspx
I just installed a second HDrive that I took from an old PC into a spare slot in my desktop PC and cloned onto that, I then disable it so nothing can affect it, this has saved me from two bad PC crashes, no need to even bother finding out what went wrong.
A remote USB drive is best so you can put it somewhere safe away from your PC, get one bigger than the one in your PC.