Windows Vista contains a very clever tool that lets you monitor the stability of your system, allowing you to troubleshoot potential problems where necessary. This rating (from 0-10) gives an indication of how stable your system is in relation to normal.
To load the tool, click the following options:
Control Panel > System and Maintenance > Performance Information and Tools > Advanced Tools > Open Reliability and Performance Manager > Reliability Monitor
The chart presented here shows your stability index rating over the past month, along with icons for every event that could effect stability. Clicking on a specific day brings up a list of Application, Hardware, Windows and Miscellaneous failures with details of the modules or processes that caused the failure.
It is most likely that driver problems and incompatibilities will cause most stability problems and this tool helps identify the modules at fault. Changes can be made and then the system stability index rated at a later date to check for improvements.