Run this tool for uninstalling
http://support.microsoft.com/mats/Program_Install_and_Uninstall

CRM 2016 download link
https://www.microsoft.com/en-us/download/details.aspx?id=50370

CRM 2016 download patch update
https://www.microsoft.com/en-us/download/details.aspx?id=55117

Manual Uninstall

Folder Paths to uninstall (depending on version)
%localappdata%\Microsoft\MSCRM -Delete
%appdata%\Microsoft\MSCRM -Delete

C:\Program Files\MSCRM
C:\Program Files (x86)\Microsoft SQL Server -Delete if only CRM using it. See folder 90
C:\Program Files (x86)\Microsoft SQL Server Compact Edition -Delete if only CRM using it
C:\Program Files\Microsoft Dynamics CRM -DELETE
%Appdata%\Local\Microsoft\MSCRM
%Appdata%\Roaming\Microsoft\MSCRM

Registry Entries to uninstall
Open Regedit

HKEY_CURRENT_USER\Software\Microsoft\Microsoft Dynamics CRM 201* for Microsoft Office Outlook
or Microsoft Dynamics 365 for Microsoft Office Outlook
or Microsoft Dynamics CRM 2016 for Microsoft Office Outlook
HKEY_CURRENT_USER\Software\Microsoft\MSCRM
HKEY_CURRENT_USER\Software\Microsoft\MSCRMClient
HKEY_CURRENT_USER\Software\Microsoft\MSCRMMsgStore
HKEY_CURRENT_USER\Software\Microsoft\MSCRMIntegration
HKEY_CURRENT_USER\Software\Microsoft\Office\Outlook\Addins\crmaddin.RibbonAddin
HKEY_LOCAL_MACHINE\Software\Microsoft\MSCRM
HKEY_LOCAL_MACHINE\Software\Microsoft\MSCRMClient
HKEY_LOCAL_MACHINE \Software\Microsoft\MSCRMIntegration
HKEY_LOCAL_MACHINE\Software\Microsoft\Office\Outlook\Addins\crmaddin.Addin

Most important:

Deleting all registry entries Look for all entries under:
Program Files (x86)\Microsoft Dynamics
And/OR
Program Files\Microsoft Dynamics CRM

Services
Stop
Microsoft CRM Outlook Client Telemetry Service
Stop SQL Server

Might be a cause for certain issues:

Uninstall
Microsoft SQL Server compact 4.0 SP1 x64 ENU

Download latest of SQL Server Compact
https://www.microsoft.com/en-us/download/details.aspx?id=17876

Then download SQL Server Compact SP1
https://www.microsoft.com/en-us/download/details.aspx?id=30709