VISA write Unknown system error

All,

I am trying to communicate with a Microcontroller using serial port. LabVIEW throws the following error at the first VISA vi Instance, let it be configuring serial port or VISA write/read.

Code- 1073807360 Description - VISA: (Hex 0xBFFF0000) Unknown system error (miscellaneous error).

I am able tp communicate to the device using hyperterminal, whereas in VISA I am not even able to configure anything.

Thanks for your help in advance.

Thanks,

Vignesh