Help ,i can't connect omt to rbs

[kiwi2010]

Sir, the situation is like this: I am using a USB to serial converter to be connected to Radio Base Station of GSM using a software called OMT after configuring the COM port on the software
and click on connect I get this message (Overlapped I/O is in progress) I am using a lap top HP EliteBook 844Op With windows 7.