The problem of your cursor jumping and freezing at some point in time during browsing or doing other activities is due to the inability of the touchpad to function properly. It can be hardware or software related problem. In the process of finding solution there is need to take to two approaches. First, is to take on software troubleshooting before doing any other thing. The second thing is to check if any of the touchpad hardware is malfunctioning or has malfunctioned.
Image of a touchpad
While it is right to look around for solutions the hardware part is usually reserved for those who are technically qualified to open and change/replace any of the failing parts or put into proper position any of the parts that has shifted from it connector.
In Dell N5040 series there is oftentimes touchpad related problem and this can be disturbing at times. If you are having this problem before taking it to your customer service center for a hardware solution this will help you to troubleshoot and forestall any DYI issues. To do that follow the step-by-step information below. Before anything you can scan your system for malicious software. To do that visit this LINK
Image showing Dell official website
STEP 1: Visit your Dell maker official website and download Chipset, BIOS(make sure it is the latest for your system) and Touchpad drivers meant for your particular system specifications. You can visit the Official Website.
Image showing Chipset installer
STEP 2: Right-click on the Chipset driver first, click open and follow onscreen instruction to install it. It will require you to restart your system for changes to take effect.
Image showing BIOS Winflash
STEP 3: **Before doing this, please, make sure you connect your system to the main power source and close every other things on the system.**
double-click on the BIOS winflash installer and follow onscreen information carefully and patiently. It is normal for the system to restart on it own after completing the process.
Image showing touchpad installer
STEP 4: Double-click on the touchpad installer and follow onscreen instruction to complete installation.
If the situation remained the same that means it is hardware related problem and must be given to a qualified personnel to fix it.