The program dwwin.exe is Dr Watson - a Windows debugging tool. You can get more info by typing drwtsn32.exe in Start - Run. Click on the Help tab. To turn off the Dr Watson debugger, apply the following Windows NT / Windows 2000 / Windows XP registry hack:
Hive: HKEY_LOCAL_MACHINE
Key: SOFTWARE\Microsoft\Windows NT\CurrentVersion\AeDebug
Name: Auto
Value: 0 disable
Value: 1 enable
To re-enable Dr Watson, you can change Auto back to 1 or from the command line type drwtsn -i.
It is likely though that your system is trying to throw a stop error. Look in Control Panel, Event Viewer, in the System log entries to see if a critical stop error has been generated.
For it is not what is seen, but what is not seen.