I have been having issues ever since installing Windows 10 on my T400 laptop where sometimes when there is a lot of disk activity the touchpad does not work. Moving my fingers across the surface of the touchpad does nothing, and the left and right buttons do not work. However, when this happens, the TrackPad and its buttons continue to work. As soon as the disk activity lessens, the touchpad starts working again. I have tried multiple versions of the UltraNav Pointing Device driver, and they all have the same problem. I figured it was just a bug with Windows 10 Technical Preview, as I don't have the same issues under Windows 7. However, I have just installed Windows 8, and I have the same issues as I do with Windows 10. A just did a quick Google search and found no solutions.
It happens in Windows 7 too. Only on newer Thinkpads. The older models never seem to have this problem.
The latest version I found is Synaptics ThinkPad UltraNav Driver 16.2.19.14 dated 08/19/2014. http://support.lenovo.com/us/en/downloads/ds019164
@MisterB This is an older ThinkPad, and I've never had that problem under Windows 7 and Vista. @zapjb There are some 2015 UltraNav drivers, I'm pretty sure I have a 2015 dated on installed under Windows 10. As for now, I have updated the driver installed by Windows, to a newer version found by Lenovo's System Update. It is not the latest driver, and is older than the one you found. But, I don't think it will help, becase under Windows 10, I have tried several different versions of the driver, all with the same result.
As I suspected, the driver update did not fix the issue. I did hope that maybe it would, since it was the driver installed by Lenovo's System Update, and Lenovo's other update tool Lenovo Drivers Management did not find a more recent driver, but I was out of luck. All of my other drivers including chipset drivers are theoretically up to date, as I just updated them with Lenovo Drivers Management.
I've found what may be a solution. I saw a post on a Microsoft forum suggesting setting SynTPEhn.exe and SynTPHelper.exe in the Synaptics folder under Program Files to run with Windows 7 compatibility. Doing so, has fixed the issue so far. I've got other issues to contend with now. All attempts to upgrade to Windows 8.1 fail, presumably because I am using a multi boot system.
I was referring to T60s and older as older. I get the Track pad freeze occasionally on a W510 and X201, both running Windows 7 64 bit. It hasn't been bad enough to annoy me. I do upgrades on a a separate HD and then image the system partition so I can put it on any drive I want for multibooting. Windows installs tend to mess with mbrs and other installed systems in multi boot setups.
