I have a compaq N600c Computer running Windows XP, it has 2 mice, one is an eraser type, and the other is a touchpad. The mouse runs off of the Synaptics driver. This evening I rebooted my computer and I noticed that my touchpad was working fine, however the eraser type mouse's motion was reversed left to right horizontaly, though the vertical motion was still normal. I have no idea what could have cause this and would appreciate any helpful knowledge about how to fix this.

Thanks in advance...Sesrun.

Since this is a new problem try a System Restore to a point prior to the problem:

start > All Programs > Accessories > System Tools > System Restore

Thanks for the suggestion, I just tried a system restore to yesterday's restore point, when i know it was working before, and it didn't fix the mouse problem...any other ideas?

Was there software installed for this mouse? If so can you reinstall it?

Otherwise look in the Device Manager: Start/Run/ devmgmt.msc

Mice ...

Here you can try to Update Driver and if that doesn't work Uninstall the mouse and reboot and XP will reload drivers.