Help!! How do I wipe my pc's memory?!

[redclover79]

Quick, help!! One of dp's mates is selling us a better pc plus in exchange for one of my old ones. But my old one is going to a friend of a friend who is going to wipe the memory and put my old memory card into the new pc. All I'm worried about is my old banking info and passwords being retrieved from the old pc and my accounts being emptied!! Does anyone know how to wipe the old pc (I think it takes a few attempts to completely clear it...) and will all that stuff be on the memory card or elsewhere on the pc?
Hope someone can help me, I have no idea how pc's work!!
TIA!

bump!

Slightly confused...

You're getting a new machine. Your old one is being sold to a friend. You'd like to erase the hard drive in your old machine before it goes to the friend's friend. Am I right?

For total security, remove your computer's hard drive, hit it very hard with a brick, then bin it.

Alternately, remove your old PC's hard drive, and put it in the new machine.

Or buy a commercial product like link{http://www.whitecanyon.com/wipedrive-erase-hard-drive.php\WipeDrive} which takes a long time to utterly blank your HD.

Or download a free one. This is the first one I found on Google, so I've no idea if it's any good.
Eraser

My personal preference would be to go for the freeware. But I'm cheap like that.

*** links!!

thanks kevlarhead, friends friend doesnt want my old pc anymore, it's too old!! Think i'm gonna wipe it anyway while I remember so will look at your links!
Like the idea with the brick too, will save that for a pent up anger day!!