Hello Graham,
- What exactly happens when you try to perform Windows Update?
- Did you try to install the drivers for the Infrared transceiver from the manufacturer's website?
Based on my research, HP offers drivers for ITE Infrared trans receiver on its official website.
I would recommend that you download and install the ITE Infrared Transceiver drivers for the HP Touch Smart 520 laptop from the link provided below.
Original ITE Infrared Transceiver Driver
Do let us know the results.