Try this
http://www.recuva.com/
Try this
http://www.recuva.com/
you flip it the other way round (its upside down), put an ide cable in the spot with those many pins (it has a slot in the connector so it cant be installed the other way round), connect the other end of the ide cable to your computer (should be an empty ide plug available), plug in a molex (power thing from your power supply) in the slot that in your picture is on the left side (also foolproof), start the puter and kaboom, it should work
it is simple but you might be a little nervous about connecting hard drive but both power and ide ribbon cable connectors are keyed so you can only connect them the correct way using normal amount of force (i have seen someone's computer and they managed to connect ide ribbon cable backwards for some reason it wouldnt boot )
i have tried this program briefly it runs a lot quicker then the one i suggested and is a lot simpler to use and is also free (i have added it to my little tool box of programs never know when something like that will be needed)
sounds like you are a little unsure about doing any of this so you may feel a bit more comfortable using old computer however old computer more then likely is using hard drive already connected to ide channel (most like sata on new comp) so you may have to change jumper setting (master/slave) on hard drive to get it to work, if you do need to change jumper settings on hard drive normally these a sticker with info on hard drive indicating where jumper need to be for drive to be master or slave, currently it should be set for master or unplug ide cable going to cd/dvd drive and unplug it from cd/dvd drive end and use that cable, at least you wont have to worry about jumper settings