If your touchpad isn’t working at all after upgrading to Windows 10, you’ll need to plug in a USB mouse temporarily to try to fix things.
Device settings
Next, click Start > Settings > Devices > Mouse & touchpad. Scroll down and click Additional mouse options.
In the window that opens, click the tab for your touchpad (this is sometimes called Device Settings) and see if your touchpad is shown as enabled.
If not, click the Enable button > OK.
Find new drivers
If this doesn’t solve the problem, you should refer to your laptop manufacturer’s website to download and install the latest drivers and software for your touchpad.