old data

If the drive is still accessable (IE it hasnt been damaged to the point that it wont spin) you can do a number of things to get the data off.

1) if you have a system of the EXACT same motherboard you can use that. (that is if windows wasnt destroyed)
2) you can slave the drive off of another computer (depending on the type of drive. Ie if it's a notebook hard drive you'll need an adapter) If it's a normal IDE drive, you can slave it to another desktop that has an IDE cable if the computer has two slots on the IDE cable or if the cd drive has an ide cable you can use that. if it's sata you can normally use the cable that goes to the cd rom as well if that cd rom is sata as well. as long as it's not in a true raid configuration.
3) there are adapters you can buy that have usb connectors to connect to a computer externally, you can do this with a notebook hard drive as well.

Now if the drive is damaged, there are always places that offer data recovery.

Hi! sospro,

by "... no longer in computer", do you mean that the harddrive is not plugged in?

In order to get data off a harddrive, you need to plug it in to an already working machine. Usually a hard drive cable has two connectors for hard drives. Turn off your computer; set the jumpers on the old HDD to slave position. Then, connect this to the second connector position on the HDD cable. or on a seperate IDE cable from the motherboard. Now when you sart your computer, this other hard drive will appear as a second drive under My Computer

If i'm not too clear, or you're asking about something else, please post back.

Ash

Buy an external hard drive enclosure.
They are usually USB connection and great for future applications as well.
So it is money well spent.