If have a unit that you are using in tablet mode and the taskbar is to large and need it to be reduced you can do this by adding a registry setting.

1) Open regedit

2) Navigate to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced

3) Right click and click New then DWORD

4) Name it TaskbarSi and leave the value as 0 and press enter

5) Right click task bar at the bottom and open task manager

6) Type Explorer to bring up that task

7) Right Click Windows Explorer and click Restart

8) Now your taskbar should be a lot smaller

If you have an organization to deploy this to you can create the reg file and deploy a script to install it or create a rule in your GPO to have it add this reg entry for all your users.