Hi i have removed ( deleted ) some contacts.
How can I get them back if I don't know their hotmail?

I dont think you can.

Sorry Alexander, I don't think there is a way of getting these back If you only deleted them from MSN, then they may still be listed in your Hotmail contact list - go to your inbox, and then contacts, and you may find them there, but this only works if you didn't delete them from MSN Messenger and Hotmail

there is no way tht u can add them bakc to ur list unless u know their email address..

May be you have deleted them from msn but they are still in your hotmail contacts. Log into your hotmail and click on the contacts and see whether they are there.