This helped, thank you so much! We're getting there, I can now at least open System Restore, although I can't run it because I need to turn it on from the System Protection tab which still doesn't work.
See if you are able to enable search for drives and thus enable system restore.
How would I do this? It may well resolve the problem, seeing as it looks like that's where it's getting stuck.
2. Your COM+ catalog might be corrupt and it needs to be rebuilt. Download the Com+ Fix zip file, extract it to your desktop and run "rebuildCOM1.bat".
This also may well fix it as I remember reading about how the COM+ catalog might be corrupt, I checked that the service had been started already, but Microsoft didn't give a clear indication of how to actually fix it. Thanks again for this, I'll have to try that tomorrow morning and let you know how I got on.
3. Also, try to see if you can run system restore in safe mode.
That was obvious. I don't know why I didn't try that already.
Again, massive thanks. You've already been more helpful than the entire Internet.