Windows 10 1803 Scrolling Down Problem

Press Windows key + X
Click Device Manager
Expand Mice and other pointing devices.
Right click on the Mouse and click uninstall

Press Alt + F4
Press the Windows key + X
Press the letter U
Press the letter R

Restart

OR

Press Windows key + X
Press the 'M' key
Press tab once
Use the down arround to select Mice and other pointing devices.
Press the right arrow to expand Mice and other pointing devices.
Use the down arrow again to select your HID-Compliant mouse
Press the right click menu key on your keyboard (usually located between the Alt and Control keys)
Select uninstall
Hit Enter

Press Alt + F4
Press the Windows key + X
Press the letter U
Press the letter R

Restart

Other things you can try.

Method 1: Try using an external USB mouse and check if the mouse pointer will appear.

Method 2: Run the Hardware and Devices troubleshooter. This troubleshooter finds and fixes common problems with devices on your computer.

Click Start.
Type Troubleshooting, and select Troubleshooting in the results.
In the new window, click Hardware and Sound.
In the list of options, click on Hardware and Devices.
Click Next and follow the on-screen instructions.

Method 3: Update the touchpad driver. An outdated or incompatible driver can cause problems. Check to see if an updated driver is available.

Method 4: Use the System File Checker tool to repair missing or corrupted system files. This allows users to scan for corruptions in Windows system files and restore corrupted files.

Open Start, type: CMD
Right click CMD
Click Run as administrator

Type in at the prompt OR Copy and Paste these one at a time : (Hit enter after each)

Dism /Online /Cleanup-Image /CheckHealth

Dism /Online /Cleanup-Image /ScanHealth

Dism /Online /Cleanup-Image /RestoreHealth

Also run the System File Checker utility:
Open Start, type: CMD
Right click CMD
Click Run as administrator

At the Command Prompt, type: sfc/scannow

This will check for any integrity violations

Restart your system

Press Windows key + X
Click Task Manager
Click File > New Task (Run)
Type: CMD
Hold down Shift, click OK