I often get an error message of MDATA.DAT every time I restart my computer. What does this mean?
That’s an interesting question! Maybe several of you get this message every time you turn your computer on and you’ve just been living with it, because it doesn’t really do anything to your system. Although it may not hurt your computer, it can be rather annoying, so it would be nice to get it rid of it! So, here are a couple things you can try.
First of all, this error message usually refers to the mouse. If you have recently installed a new mouse on your computer, you may need to remove the software that came with your mouse and see if you can pinpoint the problem that way. So, if you do have a new mouse, go to Start, All Programs, Control Panel, Add/Remove Programs. Look around in there for the company name of the mouse or anything that might be related to the new mouse and remove it from the list. Once all of that is removed, reconnect your mouse, restart your computer and update the drivers.
To update the drivers, go to Start, All Programs, Control Panel and double click on the Mouse icon. (Make sure you are in the classic view  in the Control Panel for this). Now, choose the Hardware tab (may be the General tab for versions older than XP) and click on the Properties button. Under here, you’re going to want to choose the Driver tab and then click on the Update Driver button. Just follow the steps and then restart your computer when you’re done.
If there is no driver update available, you can can click on the Uninstall button and go about removing it that way. When you do that, you will receive a “Confirm Device Removal” box. Just hit OK. You don’t have to worry about Windows not recognizing your mouse when you restart your computer, because it always will. You will then just have to restart your computer again so the changes will take effect. You may even be prompted to restart again just to make sure the configurations you made are kept.
Now, you’re probably wondering what you do if you haven’t recently started using a new mouse. Well, if your old mouse is giving you problems with the MDATA.DAT error message, you can try a little troubleshooting. Go to Start, All Programs, Control Panel and click on the Mouse icon. Once there, go to the Hardware tab (General tab for older Windows versions) and click on the Troubleshoot button. This will then run a diagnostic test to see if your mouse is working properly or not. If the test comes back and says that your mouse is working right (even though you know it isn’t!), you can go back to the Hardware tab and click on the Properties button. You can then follow the same directions as above to update your drivers and see if things can be fixed that way.
Hopefully, with either uninstalling or updating, you will be able to find the mouse problem and the error message will be gone forever. And if it ever has nerve enough to come back, you will know how to fix it right up!