I have a PC that has seen XP, Vista, W7 and now W8. I also have a little fan heater that I use to keep me warm when I'm using this PC. Every time I turn the fan heater off I get the 'You have unplugged a USB device' noise from the PC. This happens consistently and has happened with all four operating systems. Is my fan heater haunted?

Yes

Time for an exorcism of that electric burnng fan heater!

This must be one of the few posts on Thaivisa regarding a fan heater, and a USB one to boot.

You heater is certainly haunted, could be time to switch to gas

Is it plugged into the same outlet (or the other half of a double)? Probably an electrical switching spike confusing the USB interface.

It's plugged into a different wall socket across the other side of the room.

It's plugged into a different wall socket across the other side of the room.

With Thai wiring it can still be the cause...

I can get my big LCD TV to briefly blank the screen briefly by turning the main ceiling light on! Who knows what is interconnected...

Have to say, the mention of a fan heater made me smile. I'd almost forgotten what they are. I have a B&O sound system connected to a TV in the bedroom. Very occasionally it will suddenly make an extremely loud humming noise. I discovered by accident that switching on/off any light makes it go away. Who knows?

Do you have any external USB devices? Or perhaps an intelligent UPS? At a guess I would say that the voltage fluctuation is causing a USB device to momentarily go offline. Doesn't the "unplugged a device" notice tell you specifically which device?

It's plugged into a different wall socket across the other side of the room.

With Thai wiring it can still be the cause...

I can get my big LCD TV to briefly blank the screen briefly by turning the main ceiling light on! Who knows what is interconnected...

I'm still trying to work out why you would be using a fan heater in Thailand?

Congratulations, you discovered the electromagnetic interference I bet PC is not grounded...

Any long USB cables plugged in?

Sent from my Desire HD using Thaivisa Connect App

Another probable cause is the dodgy power supply that can't keep the voltage levels stable

Sent from my Desire HD using Thaivisa Connect App

I'm still trying to work out why you would be using a fan heater in Thailand?

I have two of them (oil radiator style with fan), the cool season in Chiang Mai or further North can get quite cool and uncomfortable.

I'm not in Thailand. I'm in a country with a well regulated supply where the wall plugs cannot withstand a nuclear attack (slight exaggeration there).