I have a USB GPS product from LandAirSea.com (GPS Tracking Key). It uses usb to com port emulation. The USBSRService.exe blocks access to the virtual com port. If I stop the service and USBSafelyRemove.exe their software can see their product again.
Windows device manager does see their product and installs the proper device driver software (u-blox ANTARIS 4 GPS Receiver (COM5)).
If I force their product to use a different com port through device manager, windows'll say the port is in use while your software is running.
I'm using Vista Ultimate 64 sp2.
SafelyRemove Ver 18.104.22.1685