Am I right in this, if PnP is disabled in the BIOS then the OS has the PnP facility, I've read this from my manual but just need to be sure. Also would setting the BIOS default correct the problem?
Its really not a problem if everything is working correctly.
Most times if people are having trouble with plug and play devices the solution is to disable it and let bios take care of it.
You can change the pnp setting in bios and let windows take care of it.
If you have troubles with anything after, just change the setting back.