Dual Monitors Randomly Swapping sides

Dual monitors are set up in the control panel - display - screen resolution as Monitor 1 on the Left and Monitor 2 on the Right. The mouse moves between the monitors normally, stopping at the far right on monitor 2 and far left on Monitor 1. It all looks good.
Randomly during the day the mouse changes direction and starts moving between monitors in the opposite directions.
Any ideas what would cause this? Is it a combination of short cut keys?

Shouldn't be shortcut keys, but..........

When you say the mouse changes direction, do you mean it actually moves in the opposite direction of what you are moving the mouse or do you mean it moves between monitors the opposite of what you want?

Anyway, what is your graphics card? In NVidia you can change the monitor orientation by dragging one screen to the right or left of the other and then setting the one as default. If you haven't explicitly done this in the card's software, I would try resetting it there first.

Sorry, the mouse moves between monitors the opposite of what we have set. We have set the monitor orientation by dragging screens. At any point during the day the mouse just changes direction. Our short term solution is to reset the monitors or just pick the monitors up and manually swap them around. We can do this 3 or 4 times in a day. It just changes on it's own.

Obwan said:

Sorry, the mouse moves between monitors the opposite of what we have set. We have set the monitor orientation by dragging screens. At any point during the day the mouse just changes direction. Our short term solution is to reset the monitors or just pick the monitors up and manually swap them around. We can do this 3 or 4 times in a day. It just changes on it's own.

I doubt that it is a software issue, but if it could be that the video driver fails and then 'recovers'. However you would get an on-screen message for that. You might want to do a 'clean install' of your driver so that it installs a completely fresh version.

But I'm suspecting that the video card loses the physical connection to one of the monitors for a second or two and defaults back to 1 monitor. Then immediately detects the other one and brings it up but in the natural order that they are connected. This is probably caused by a hardware issue rather than a software one.

1. Are you used the screws on the cables or are you just inserting them? One monitor might be a little finicky about connections. On the other hand, if it is a cable issue and if you have spare cables, maybe try completely different cables first. At least that would eliminate one possible cause.
2. Your video card could be overheating on one of the connections and resets itself. If your video card has more than 2 connections, try different connections, although the card may still have the problem no matter which output you use.
3. Your monitors probably have more than one type of connector. Try using different type of cables or use adapters to use a different connection on each of the monitors.

If you do these tests one cable or monitor at a time, you can find out which was your problem. If you swap out both cables or change both connections at the same time, you may fix it but never know what caused the problem. If you don't care, then toss both of the old cables. If it's a monitor's connection. you'll be wondering next time you need to reconfigure if the monitor's connector is good or not.

In any case, good luck.

One monitor suddenly started flashing. Before rebooting I swapped the monitor out but the replacement monitor continue to flash. I then rebooted and it seems to have settled. One is connected via VGA and the 2nd DVI. I had previously tried swapping the 2 cables between monitors.
Thank you for your ideas. I will see if if settles today. If the problem returns I will replace the PC - it's doing the users head in.