You might have fall in a situation where applications crashes suddenly. Here is an application known as Application Monitor that constantly checks the processes previously chosen by the user, and when it detects that one of those processes has stopped working it will start it again.
Have a look :
With Application Monitor you will always be sure that your important processes are running. AppMonitor has been developed keeping in mind all those admin and power users who use programs that must always been running (such as webserver, database, mailserver, p2p) and that don't have a built-in restart function.
System Requirements :
Operating System : Windows 98 - ME - NT 4(service pack5) - 2000 - WindowsXP
Libraries : You must have installed the Microsoft .NET Framework 1.1 or higher, freely available on Microsoft site.