Last night my friend bought an IR-Serial module, so I got it receiving data from household Remotes, etc... at a Baud of 115200, however when using WriteFile to write to the open COM the computer locks up. So then I used SetCommState to set only afew settings for the COM port such as Baud, ByteSize, Parity, and StopBits. However, if I change the Baud to 115200 I cannot receive data from the remotes, but if I set it to any lower setting I can receive data. I am wondering if I must somehow synchronize the BaudRate to devices that I want to work with. I have not resolved the problem with the application locking up when I am using WriteFile, I decided to look at what other people have done with Serial reading/writing they all seemed to use OverLapped I/O, and in one sample one person used SetEvent, to set the COMM event into a Write-State, but I dont think either of those should have an effect on the serial its self; When I send data it might range from a buffer size of 500-3100 bytes(since I am just trying to synthesize the same pattern as a Remote Control for a test). If there are any limits to what kind of data a Serial can send, and the lengths that it can send at a time, or any other information if anyone has used an InferRed before, please dont hesitate to respond Thanks