If you faced the issues like Windows service(s) may be abnormally exited , java (JVM) may throw "EXCEPTION_ACCESS_VIOLATION" error, ... etc. then please check the "Event Viewer". You may find the error message like "The computer has rebooted from a bugcheck. The bugcheck was .... . A dump was saved in c:\windows\minidump\mini002509-01.dmp"
More details on this available in the following URL:
http://msdn.microsoft.com/en-us/library/ms794023.aspx (You can check based on the bugcheck code)