The touchpad on your laptop worked fine before. But just now, the two-finger scrolling stops working, nor do other functions on your touchpad work. Besides, you’re seeing this error saying Unable to connect to the Synaptics Pointing Device Driver. Now you must be annoyed by this problem. But don’t worry, you CAN get your touchpad work again.
This error occurs mainly because the wrong, corrupted, or missing Synaptics device driver on your laptop. You can solve it through cleanly reinstalling a correct Synaptics driver for your touchpad.
Follow these:
First, Uninstall all the Synaptics device driver on your laptop
1）On your keyboard, press the Windows logo key 
and R at the same time to invoke the Run box.
2) Type devmgmt.msc and press Enter.
3) Right-click on your Synaptics drivers one by one to choose Uninstall, they could be Synaptics PS/2 Port Touchpad, Synaptics SMbus Tochpad, Synaptics Pointing Device, etc.
Then, download and install a compatible latest Synaptics touchpad driver for your laptop
You can download the latest Synaptics touchpad driver from your laptop manufacturer’s website as Way 1 shown. You should never download the driver from a third-party website when you’re not sure its security. If you’re not familiar with updating drivers manually, follow Way 2 please.
Way 1: Download and install the latest Synaptics touchpad driver manually
Way 2: Update your Synaptics touchpad driver automatically [RECOMMENDED]
Way 1: Download and install the latest Synaptics touchpad driver manually
1) Go to your laptop manufacturer’s website, like DELL, Lenovo, HP.
2) Find the specific driver download page; usually it locates in the Support section.
3) You will need to enter your laptop’s ID or the model number and locate your Windows operating system.
4) Find and download the latest Synaptics driver. It’s usually under the Mouse and Keyboard section.
5) After downloading, double-click the .exe driver file and follow the on-screen instructions to install the new driver.
6) With the new driver installed, restart your laptop and check to see if you could use your touchpad.
Way 2: Update your Synaptics touchpad driver automatically [RECOMMENDED]
You can update your Synaptics driver automatically with Driver Easy. Driver Easy will automatically recognize your system and find the correct drivers for it. You don’t need to know exactly what system your computer is running, you don’t need to risk downloading and installing the wrong driver, and you don’t need to worry about making a mistake when installing.
Follow these to quickly and automatically update your drivers:
1) Download and install Driver Easy. Then run it on your Windows.
2) Click Scan Now. All drivers problems of your computer would be detected in less than 1 min. Your Synaptics driver is no exception.
3) If you try the Free version, click Update next to your flagged Synaptics driver to automatically download and install the correct version of this driver.
Or if you use the Pro version, click Update All to automatically download and install the correct version of all the drivers that are missing or out of date on your system.
4) Restart your laptop and check to see if you could use your touchpad.