synchronization

[rabnawaz42]

A synchronization barrier primitive that allows multiple processes to block on an event until some other process triggers the event. When a process triggers the event, all processes that are blocked on the event are unblocked; the operation has no effect if no processes are blocked.

Give Me Some Hint How Should I Start

[kbw]

http://msdn.microsoft.com/en-gb/library/windows/desktop/ms686364%28v=vs.85%29.aspx

[writetonsharma]

http://msdn.microsoft.com/en-us/library/windows/desktop/ms687025%28v=vs.85%29.aspx

[rabnawaz42]

no its for threads i said for across a process

[writetonsharma]

you can use them for processes also.

[rabnawaz42]

by process i does not mean CreateProcess();
by process i mean the two separate programs

[S G H]

You should be able to use MUTEXes through Processes.

See here:

http://stackoverflow.com/questions/4191465/how-to-run-only-one-instance-of-application