How do I permanently delete my msn/hotmail email address?

It has been usurped by scammers and spammers who have been sending spam for viagra and other crap to my email contacts even while I'm not online, it's become embarrassing.

The last straw was when a friend responded to a fake email today that had addressed her by name and asked her was she going away for the Christmas holidays! - with an attachment that she didn't notice for some berries.

Here is the transaction (note - I didn't send the first message);

From: Kenneth O' Neill (ken@********)

Sent: 18 December 2010 03:27:35

To: anne.murray@*******

Anne hello are you leaving town for Christmas? I always eat a lot over the Holidays. I never thought acai berry could change my life! http://bit.l********/

Anne Murray Anne MurrayAnne.O'Neill@******

Sent: 20 December 2010 09:55:06

To: Kenneth O' Neill (ken@******)

Hello Ken

No, we are staying in Dublin for Christmas, call up St. Stephen’s Day for a drink.

Anne

18/12/2010

I reluctantly have to delete this email account that I have used for years, how do I go about it? I checked all the options on my email homepage but there is no option to 'delete account'.

Any help would be greatly appreciated.

Ken