Evidently there are a couple of different versions of this same file name. One can be a trojan/keylogger type and one is the program associated with yahoo messenger that runs at startup (you can turn it off supposedly in MSCONFIG/Startup tab) and notifies you when somebody else in yahoo is trying to reach you.
Here's one link that describes some problems with it:
And another link from google giving other links so you can read about it and decide what you should do (uninstall/disable it) or leave it alone.
out of the blue i receive an error window as follows "Ypager causing an error in unknown window and will close now". i have Windows/ME, aol 8.0 and yahoo messenger.......how can i correct this situation.