Close Microsoft Outlook.
Right-click the Salesforce for Outlook system tray icon and click on Exit.
Use the Windows and R key combination to bring up the Run box and type in Appwiz.cpl to bring up the list of installed applications on your machine (you can also navigate to Control Panel\All Control Panel Items\Programs and Features).
Select the Salesforce for Outlook and click on Uninstall and follow the on-screen instructions.
First follow the instructions above to uninstall SFO.
Next, Press Windows + R on your keyboard to open the 'Run' command prompt screen.
Enter %AppData%\Salesforce.com\
In the folder that opens, right-click the 'Salesforce for Outlook' folder and select Delete. This removes the user settings and SFO sync database.
With these steps complete, you have uninstalled SFO from your computer.
Go to the installation instructions for Salesforce-Outlook Integration.