Using a 20-pin connector in a 24-pin slot...

Hey /comp/,

I'm a novice when it comes to building computers, and this is the first time I have come across this.

I have a PSU that has a 20-pin connector.  My new motherboard has a 24-pin slot.  I asked the guys at a computer shop nearby if I needed an adapter, but they said no; I could plug the 20-pin into the slot with no problems.  I don't want to blow anything up, so I thought I'd ask /comp/ also before I went through with it.  Any answers?

Windows stores a hash of your hardware and will refuse to boot under major changes. It's to prevent people from stealing your harddisk and probably also to prevent piracy. You must reformat after you change many/major components.