Hello and a question

[Jmh474]

Just like to say hello first, I stumbled across this forum and thought that I would ask my question here.

So I was at a car boot and come across a Odb2 to DB9 lead for a few quid, asked a few questions and now I'm not to shore.
Think he was just after a sale.
From what he told me I can just plug this straight into my old windows 7 laptop then just install and run some software.

But I have a feeling that some thing is missing.

My question is am I right or wrong and what software she I install??

Well thanks to ever can help and advise

me

This is the same lead in question

[Jmh474]

I have a fiat punto mk2 2004, I just wanted to run some diagnostics over the car in real time as it seems judder in 2nd in low revs, and just to have a little play about as all things electronic interest me.
Yes my laptop has a serial port for the cable and is running Windows 7 32bit