One of the first mitigation solutions that you need to turn to in case your copy of Windows Vista fails to start correctly is System Configuration. Via this advanced tool, you will be able to identify the program that is at the root of the start failure and you can either update or uninstall it completely.
"Using the Selective Startup option, you can turn services and startup programs on or off individually to see if the problem occurs the next time you restart your computer. If you select a check box, the service or startup program will run when you restart Windows. If the check box is cleared, the service or startup program will not run when you restart the computer," Microsoft informed.
While using System Configuration to mitigate startup issues, you have to keep in mind that the tool is designed to address isolated incidents. Do not mistake the tool for a startup management program. That being said, System Configuration can be accessed via Start, Control Panel, System and Maintenance, Administrative Tools. Additionally, you can simply enter "System Configuration" in the Start Menu search box and the tool will immediately be highlighted.
In the General tab of System Configuration bellow Normal Startup and Diagnostic Startup, you have the Selective Startup options. Simply select Selective Startup and clear both of Load system services and Load startup items. Next enable only Load system services and then restart your machine. If the problem persists, make your way once again to System Configuration.
In the Services tab, disable all and only enable one at a time. Each of these actions must be followed by a restart in order to identify the service that causes problems. If the Services are not faulty, then select the Startup tab and repeat the process with the startup items.