On my other PC, the mouse pointer is bouncing around the screen. I've been away for a few days and it wasn't doing this before.
The pointer is hopping from spot to spot in what could be a chaotic motion i.e. I can't see a pattern. It hops several times per second and each hop is usually no more than a couple of inches across my (26") screen, usually in a different direction, but over time it's migrating around the whole screen. Both button clicks are also happening: whilst I was pondering on it, it managed to change to the High Contrast display theme.
I've never seen anything quit like it. The nearest thing was way back when I was playing with plotting mathematically chaotic equations.
I am not moving the mouse.
Although the symptoms appear similar, this is not an exact duplicate of "Why is my mouse pointer moving on its own?" - in that question, the pointer remains on the far right of the screen unless the mouse is moved. In this question, the pointer is flickering around across the whole screen but responds partially to mouse movements, by moving the centre of the flickering around the screen. The only similarity between these questions is that the pointer is not behaving as it should - the actual behaviours are entirely different.
I've solved it. It's fair to say that my office is in a bit of a mess at the moment whilst we redecorate another room. I have a Wacom Bamboo tablet which I hardly use these days. It'd fallen down the back of the desk and my laptop PSU had landed on top of it.
I was going through the unplug-everything-one-by-one routine. I'd already tried unplugging the mouse as soon as the problem manifested itself but that didn't help. I was going through the USB cables, unplugged one and it stopped. When I plugged it back in, it started again. I followed the cable and found the long-forgotten tablet, with the PSU sat on top of it. As soon as I moved the PSU, it stopped. With a bit of trial-and-error I found that it didn't need to be in contact to cause the problem.
Anyway, thanks for the suggestions.
After two months of working correctly, I am experiencing an strange and very annoying problem. My mouse pointer is moving on its own. If I move the mouse to the left, as soon as I stop the movement, the pointer runs again to the far right. This makes the mouse totally unusable.
The mouse device is an optical USB mouse.
It is not a problem with the mouse itself. I have tried with another mouse, same problem. (both mice are OK, I have tried both mice on my laptop, both worked perfectly)
Have tried different surfaces, too. Same problem.
System is Windows XP Pro SP3. Computer is a desktop PC two months old.
I suspected it could be a problem with the mouse driver. But both mice are from different brand, so I suppose they use different drivers.
Related Question: Why is my mouse pointer twitching?
Related Question: Why is my mouse pointer twitching?
What surface are they on? Cheap optical mice can really be thrown off on some surfaces.
I have solved the problem. I am explaining what I did, for the record. Hope this helps someone else. I don't know exactly what step did solve the problem, anyway, here is the complete things I did.
I first changed different settings in mouse control panel. I set a lower pointer speed and disabled the enhanced pointer precision setting. And I disa bled the device.
I restarted the PC.
After restarting, I enabled the device back.
Now the mouse works correctly. Although its speed is a little lower.
Make sure there's no dust bunnies blocking the laser's point of exit from the mouse! This happens to me all the time.
I came to our computer club and set up, then found that the mouse was erratic, always working its way to the top left of the screen. Very irritating.
I didn't have the problem at home, so I knew it wasn't the mouse OR other hardware OR software! The problem was simply the kind of mat I was using, a sort of plastic pad.
This will be a solution for only a very few. About a year ago I bought a wireless optical mouse. Once again (I had one before) after a few months I had trouble with it, so I said, "@#*#%@^"; I've had it with wireless. I'll get a corded optical mouse, and did so.
Well, my corded mouse after about a year started acting up. The mouse pointer would dance a little jig whenever I stopped moving it. At intervals of about a second or so it would have a quiet spell before it started dancing again. I tried every answer listed above. No luck.
Then I noticed that there was a device that looked like a flash drive right next to the USB port I was using for the mouse and it was flashing at about the same frequency that my mouse was jigging. I pulled it out; it wasn't a flash drive; it was the receiver for my wireless optical mouse that I neglected to remove when I tossed the wireless mouse. My mouse pointer is now rock steady.
I know this is a very unique solution but it might help some of you.
I had a similar problem. See http://superuser.com/questions/48678/microsoft-optical-mouse-cursor-moves.
I selected the answer which had to do with a dark background, and it seemed to work
However, just this week I had to replace my mouse also as it failed completely.
I believe there were 2 proper answers: Black background and : failing mouse