How to Stop an Application from Opening at Startup on a Windows XP PC

Using the System Configuration Window

1. 
   Click Start and then click Run.
2. 
   Type MSCONFIG and tap . The System Configuration window will pop up.
3. 
   Click the Startup tab.
4. 
   Uncheck the programs you do not wish to run on startup, and click OK.
5. 
   Restart the computer for the changes to take effect.

Using the Registry Editor Application

This method will permanently delete start-up items

1. 
   Select "Run" from the Start menu
2. 
   Type REGEDIT and click OK.
3. 
   The registry editor application will open. Use the tree view on the left to navigate to HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersion.
4. 
   Check the subkeys Run and RunOnce for a path to the application you wish to stop starting automatically at startup. If you find such a path, right click the individual path and click "Delete" from the pop up menu.
5. 
   If you choose to delete a value, a dialog will result to confirm the deletion. Click "Yes" if you really wish to delete the selected value. Note: The above steps assume that the program is running for every user on the computer. HKEY_CURRENT_USER contains the same path and keys for the currently logged on user.