How to Completely Uninstall / Remove a Software Program in Windows without using 3rd Party Software?

We have divided this tutorial in 4 steps:

• Uninstall Using Control Panel
• Delete Remaining Files and Folders of the Program
• Remove Software Keys from Windows Registry
• Empty Temp Folder

• STEP 1: Uninstall Software Using Control Panel

  First thing first! Uninstall the software using Windows Control Panel.
  Windows XP and earlier:
  Open Control Panel, double-click on "Add/Remove Programs", select the program name and click on Uninstall button. It'll remove it.
  Windows Vista and later:
  Open Control Panel, click on "Programs and Features", select the program name and click on Uninstall button.
  

  STEP 2: Delete Remaining Files and Folders of the Program

  Even though you have uninstalled the software using Control Panel, some files of this program might still remain in a few system folders.
  To delete these leftovers, you'll need check following folders:

  %programfiles%
  %programfiles(x86)%
  %appdata%

  If you find any folder with the name of the software program which you uninstalled using 1st step, delete it.
  NOTE: You just need to type the above mentioned text in RUN or Start Menu search box and press Enter. It'll open the folders directly.
  Program Files folder:
  
  Application Data folder:
  
  NOTE 2: 64-bit system users will also need to check "C:\Program Files (x86)" folder. Here we assume your Windows is installed in C: drive. If you installed Windows in any other drive, replace C: with that drive letter.

• STEP 3: Remove Software Keys from Windows Registry

  To completely uninstall the software, you'll also need to delete its key from Windows Registry.
  1. Type regedit in RUN or Start Menu search box and press Enter. It'll open Registry Editor.
  2. Now go to following keys one by one:

  HKEY_CURRENT_USER\Software
  HKEY_LOCAL_MACHINE\SOFTWARE
  HKEY_USERS\.DEFAULT\Software

  64-bit system users will also need to check following extra key:

  HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node

  Once you go to the above mentioned keys, look for a key with the name of your uninstalled software. If you find a key, delete it.
  If you get an error while deleting a Registry key such as "Cannot delete key: Error while deleting key", you'll need to take ownership of the key as mentioned in following tutorial:
  How to Take Ownership (Permission) of a Registry Key in Windows?
  Sometimes the key name might be based on the company name or developer name so if you suspect a key, expand it and check whether its related to the uninstalled software program. If yes, you can delete it.
  
  PS: Make sure to take a backup before deleting anything from Windows Registry so that you can restore it later if something goes wrong. To take backup, right-click on the key which you are going to delete and select "Export". It'll save a .REG file containing the backup of that key.
  PS2: Expert users can also find all occurrence of the key with the name of uninstalled software using "Ctrl+F" and delete them. You'll have to be very cautious for it. Delete the key only if you are absolutely sure that the key was created by the uninstalled software.

  STEP 4: Empty Temp Folder

  At last you can also empty Temp folder which contains temporary files and cleaning this folder is absolutely safe.
  To empty Temp folder, type following one by one in RUN or Start Menu search box and press Enter:

  %temp%
  temp

  It'll open Temp folders. You can empty them. If Windows shows errors while deleting a few files, leave them. These files might be used by some running software or Windows services.
  
  That's it. After following the above mentioned steps, you'll be able to completely uninstall and remove a software program from Windows.