You can  Speed Up Startup and Shutdown By Disabling Unnecessary Services and Programs that you don't need.

Having too many programs or services run automatically can slow down your system performance and also slow up startup and shutdown times. 

Some programs are better left to run automatically such as antivirus programs and background services but other programs such as Yahoo chat or messenger are not required at startup and can hamper system performaceSome programs. You may need to look in several places to stop programs from running at startup such as:

1. The Startup folder
2. System Configuration Utility
3. Scheduled Tasks
4. Logon scripts
5. Registry settings
6. Services

Clean out the Startup Folder

Go to to Start/All Programs/Startup) and delete the shortcuts of any programs you don't want to run on startup.

Don't worry, you're deleting only the shortcut, not the program itself. In Windows Vista, go .)

1. As an added measure you can disable other startup programs in the System Configuration Utility
2. Go to start and type msconfig (See Figure 1.0)
3. To stop a program from running at startup, go to the Startup tab in this utility and uncheck the box next to the program.
4. Restart your PC

Figure 1.0 msconfig Utility

TIP You can bypass startup programs during startup by pressing and holding down the shift key while booting up

Clean Out Scheduled Tasks

Go to to Start and type Task Scheduler. (See Figure 1.1). Look for any tasks that you don't want to run.

Figure 1.1 Task Scheduler

Look at the Triggers column and see whether any tasks are listed "At system startup." Click Delete if you want to removed the scheduled task. Click through the tabs to get more detals ont he scheduled task.

Stop programs in the Registry

You can hack the Registry to disable additional startup programs.

Go To Start and type regedit and go to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run. Look at he right paneto see a list of some of the programs that run automatically at startup. The Data field tells you the path and name of the executable so that you can determine what each program is. Right-click any program you don't want to run, and choose Delete. That will kill any programs that run and are specific to your account.

To kill programs that run for every user of the system, go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run and follow the same procedure as above.

Shutting Off Services that Run at Startup

You can disable a service in the msconfig utiltiy from above by clicking ont eh services tab, however, it does not lista ll the servifces and provides few details ont eh purpose of the service. A better way to disable services is to go to the Services Computer Management Console.

1. Go to start and type services.msc.
2. Click the Extended tab

The Services Computer Management Console includes a description of all services so that you can know ahead of time whether a particular service is one you want to turn off. It also lets you pause the service so that you can test out your machine with the service off to see whether it's needed.

After you run the console, . This view shows you a description of each service in the left pane when you highlight the service. The Startup Type column shows you which services launch upon startup—any services with "Automatic" in that column. Click the top of that column to sort together all the services that automatically launch on startup. Then highlight each service and read the descriptions.

When you find a service that you want to turn off, right-click it and choose Properties. In the Properties dialog box that appears, choose Manual from the "Startup type" drop-down list. The service won't start automatically from now on (unless another service requires it in order to start), but you can start it manually via the console. If you want the service disabled so that it can't be run, choose Disabled. (If you disable a service that a critical Windows service depends on, that service won't be able to start either, which could cause problems.)

To test the effects of turning off the service, turn off any services you don't want to run by clicking "Stop the service" in the left pane, or by right-clicking the service and choosing Stop. Note that some services can't be stopped while the system is running. You'll have to set them to "manual" and reboot to see the effect of turning them off.