serial communication problem - TargetSrv.drv

[JamesJ]

I have communication to a compumotor stepper motor through RS-232 serial
port, from my labview application.  It was working properly without any problems initially.  But recently motor
doesnt respond.  However i can communicate to the motor controller from hyperterminal.  But cannot communicate from the labview application.

There is an application called TargetSrv.drv running in the background.  I dont know what this is.  It came with the new dell PC.  When i manually stop thisapplication, then i dont have communication problem from my labview application. 

I am using  LabVIEW  version 7.1
I have Visa Driver Version 3.1 installed
OS :  Windows XP

ThankYou in advance

JAMES JACOB

[JoshuaP]

Sounds like that service is somehow using the serial port. Windows will only allow one application to use the serial port at a time and if that service is some how using the serial port, Windows will block NI-VISA from using the port. Call Dell and ask them what it is. You can probably disable the service by right-clicking on My Computer and select manage. Find the service under the Services folder and change the service from Start Type automatic to manual.

-Josh