You could try the following:
Got to the PC's BIOS and set the parallel port to one of the following:
Unidirectional, Output only, Normal, SPP.
Do not set it to ECP, EPP or Bidirectional.
The second solution could be as simple as choosing a different LPT number, try this, choose LTP2, LTP3, in the Picoscope software, sometimes on NT based operating systems the LTP numbers of mixed up. This seems to be caused by the operating system virtualising the port.