Synaptics Touchpad driver: Missing Synisdll.dll, can no longer repair driver.

I'm on Alienware 13 R1 with Windows 10 Pro installed.

I noticed I could no longer scroll up or down on the browser page with 2 finger touch gestures, and could not bring up a context menu by tapping with two fingers for right clicking.

Felt there may be an issue with the touchpad driver. Decided to repair the drivers by reinstalling the touchpad drivers. When uninstalling the touchpad driver, it said "Synisdll.dll" is missing. Then, I went ahead to try installing Synaptics touchpad driver downloaded from the Dell drivers page. The installation detected Synaptics driver, and skipped the whole installation process.

I wanted to force reinstall the driver, but I don't know how to do so with Dell's driver. Maybe I need to go to Synaptics and get the driver from there, but I have no idea what kind of driver this Alienware 13 touchpad requires specifically.

Anyone knows how to force the installation to overwrite the touchpad drivers, or repair them?

 

If you're sure that you have a Synaptics Touchpad, go to the official Synaptics HP and donwload the newest driver. The install via the .exe doesn't work, so you have to go to the device manager, select the PS2 Mouse, choose "update driver" and then show Windows the path where the 64 bit versioin is hidden.

If you are not sure that you have a Synaptics, look at the hardware-ID in the same menu where you can choose update driver, it's only one tab further.