Misbehaving Taskbar

Whenever I start or reboot Windows, my taskbar does not appear as it was before starting or rebooting Windows. The taskbar appears as a single line with an up/down selection arrow to view the hidden icons. These are the steps I have to take to have the taskbar look and operate the way that I prefer.
1. Click on the down arrow of a single line taskbar.
2. Right click on a clear area of the taskbar.
3. Unclick 'Lock the taskbar'.
4. Increase the height of the taskbar to two lines.
5. Right click on a clear area of the taskbar.
6. Click 'Lock the taskbar.'
Now the taskbar consists of two lines, is located at the bottom of the screen and automatically slides off the bottom of the screen when not selected. In the past, I have not had this problem. It seems that a small change in an update to Windows is the apparent culprit.
What do I need to do to have the desired taskbar after I start or reboot windows?
Thank you.

Windows 10 Pro 64-bit, Version 1803, installed on 8/31/2018, OS build 17738.1000, Dell XPS-8700.

Do you have this behaviour in a single account or all accounts?

Perform the following steps:

1) open administrative command prompt and type or copy and paste:
2) sfc /scannow
3) dism /online /cleanup-image /restorehealth
4) chkdsk /scan
5) net user test /add
6) When these have completed > right click on the top bar or title bar of the administrative command prompt box > left click on edit then select all > right click on the top bar again > left click on edit then copy > paste into the thread
7) shutdown /r
8) When the computer reboots sign on with the new user named test
9) Compare the task bar with the different users

Howdy zbook,
Can you tell me where my My Documents folder is now? It used to be on my D: drive, but after I signed in and out as 'test,' the folder was no longer on my D: drive. My C: drive contains all my programs. My D: drive includes all my DATA! 99% of all my DATA is located inside the My Documents folder. And now it is missing after I followed your directions as an "elevated system administrator". I have included a copy of the test results. I hope you will be able to tell me where My Documents is located.
I know I can not prove you are responsible for the loss of my DATA. But it is conveniently coincidental that the loss of the information occurred after I followed your instructions.
I hope we will be able to solve this mystery.
Thank you.

The scannow command found a corrupt operating system and repaired it:

Code:

Windows Resource Protection found corrupt files and successfully repaired them.
For online repairs, details are included in the CBS log file located at
windir\Logs\CBS\CBS.log. For example C:\Windows\Logs\CBS\CBS.log.

The restorehealth completed normally and did not find problems with the component store.

The chkdsk scan did not find problems with the drive file system.

The documents folder should not be altered by the above commands.

The scannow command should be run again to see if the repair was or was not only temporary.

To locate the documents folder download and install Everything: voidtools

This software will index everything on internal and external drivers.
Compared to Windows search the everything search results are instantaneous.
As you enter a character there will be results and the more characters that are entered the narrower the results.

A common way to find the documents folder is file explorer > this PC > C: > Users > user named used on the computer > documents

Using everything search enter: *.documents
and look for the documents folder.

If there are any problems open file explorer > this pc > C: > users > click the users name for the applicable account > post an image into the thread