how to use event in threads

Looks like you want to know a lot about kernel objects :). Well, basically it's this way:

1. You create an event, usually by calling CreateEvent function
2. You pass handle of this event to all the threads that shall use your event. Depending on situation, there are numerous ways to do that - from passing handle in thread function arguments to duplicating it in another process
3. When any of your threads need to wait for this event to occur, you call WaitForSingleObject or WaitForMultipleObjects function, passing event handle as an argument
4. When condition being wait for is satisfied (you get the data to process, for example), another thread raises event by calling SetEvent function
5. Next time waiting thread receives processor time, WaitForSingle object returns, so this thread can continue execution
6. When needed, event can be reset (put in "not yet occured" state) by ResetEvent function, so you can repeat the process from step 3
7. When no mere needed, Event handles should be closed by calling CloseHandle methods

This is very brief and incomplete description, missing a lot of details, but it should give you the basics. Something to start with before diving deeper into MSDN :)