Well I have had fun today.
1. STOP BSOD Watcher.sys. Doing nothing in particular.
2. Decided to do sfc .scannow. Found errors.
3. Repeated the sfc. STOP BSOD Watcher.sys at about the 50% progress.
4. Aha must be IE9 install. I had problems with the early beta. Uninstall IE9,
5. sfc still corrupted.
6. System restore to just before IE9 install yesterday. sfc still corrupted
7. Image restore to Tuesday morning. sfc still corrupted. Aargh!!
8. Image restore to Sunday morning. sfc clean. Hooray!
9. Restored User files to yesterday evening. Virtually nothing of any consequence lost.
10. Windows update complains that it has never been run. Why?. Check for updates one optional found. Didn't apply as it was hardware so hid it.
11. Checked update history and it is all gone. Obviously can't be part of the image.
12. No SR checkpoints remain, but I'm not surprised that an image restore gets rid of them.
13. Thinks! I wonder if my file system is ok. Runs checkdisk which found and repaired MFT bitmap errors.
14. Runs 2 updates to programs that were backed out. Not bothering with IE9.
15. Ran an image backup.
My thanks to whs for introducing me to Macrium and to SIW2 who helped me build a recovery USB stick a while back.