Windows Live Messenger has stopped working

I've lost count of the number of times I've read the above message and its follow on comment that the program will be closed and notification given if a solution found. Plus the auto follow up message about closing for reason of data protection. No amount of uninstalls and reinstalls (of WLM) work. Any going back to an old WLM is not accepted as it advised I need to update to a newer version. Then the same result as described.

I encountered problem after setting laptop back to Vista factory settings. I have now caught up with SP2. There was a Microsoft follow up advising I should await Vista updates catching up with SP2. This has now happened but still I receive the same message each time I try to open WLM.

I have seen the problem posted previously but have not seen a solution that I haven't tried. I cannot set back to an earlier WLM. I have tried without a firewall (Norton) and disabling the webcam (logitech for notebooks) but nothing works.

There must be a definitive solution somewhere. Can anyone help please.