A. - it would probably be useful to know what version of XAMPP you are running - You might even put it in your profile along with the OS version as requested when you signed up.
B. - Are you running Apache as a service?
C. - Apache shouldn't have just 'stopped' - there was likely an error condition that caused this - what's in the error log??? Resovling that issue is probably the key. Normally on Windows, when Apache 'dies', its a 'worker process/child' that is killed off, and the MPM kickstarts a new worker process. (that's why there are two httpd processes)