Hello Syed,
Thank you for reaching out to the Microsoft Community and I'll be glad to assist you today.
I recommend installing the Intel Chipset Driver and the Intel Serial IO Driver specific to your device model to help resolve the touchpad issue.
Dell Latitude 5400 Drivers -
https://www.dell.com/support/home/en-us/product...
Additionally, Download and install the Intel HID Event Filter Driver to check if your touchpad is detected and functioning properly.
**Note:** The link provided above will take you to Dell's Drivers and Downloads page.
Standard Disclaimer: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.'
I hope this information helps. If you have any questions, please let me know and I will be happy to help you further.
Best regards,
Gunasekar N