I'm actually ashamed to need to look for help for this.

I have an old laptop with a 500GB 2.5" SATA hard disc drive in it.

Now I wanna wipe the thing to put it into my ps3 but I cant seem to figure out how to format it i.e. windows wont allow me to because the Operating system is on it. I cant find anything online to help me oddly enough, all I can find is ways to do it involving re installing the operating system, but I just want a wiped HDD.

Help?