urgent data recovery from computer that shuts down immediately after startup

I need the major steps for the quickest and easiest way to recover urgent data from a computer that shuts down immediately after startup.  Thank you

Maybe you need to be more specific.
1. Why your computer shutsdown(suddenly, previously, recently)?
2. Laptop or desktop?
3. Are you doing anything that made your data loss before computer shutsdown?
4. What kind of data are you trying to recover?
5. Are loss data connected to computer shutdown?
6. Are there previous events, messages occured to computer shutdown such as thermal or overheat?

[Moderator]

Slave the drive to a different system.

I agree with Allen, set up the hard drive as a slave on another system and you should be able to get any of the contents off that you need to.

[Moderator]

I agree with Allen, set up the hard drive as a slave on another system and you should be able to get any of the contents off that you need to.

Gee, thanks.

That's if its a desktop drive. depending on the type of shut down, if it is software related you may be able to boot a live-cd linux distro and recover small files that way.

if you do not have another computer to hook it up to to pull data off, or if you do not have any friends that can help. You may have to hit up a local computer store or greed squad. It shouldn't cost much (assuming you provide a bare drive and an external to transfer contents to)