Windows Vista operating system startup time can be reduced by making changes to the system configuration.
To access System Configuration, type msconfig in Run command and press enter. This would display the System Configuration dialog box
Under General tab select Selective startup option and navigate to the Startup tab. The Startup displays the list of services that are loaded during the system startup. Now un select the unwanted startup process which you do not require to be loaded during the System startup.
After making necessary changes, save the configuration changes by clicking Ok.