|First of all, tell your friends not to open the emails unless they are sure the messages are actually from you.|
Your email address is being spoofed, which means that someone who has your email address in his/her address book has a virus that's sending emails out that appear to be from you. If your friends are opening the emails, they risk infecting their systems as well if unprotected.
There's nothing you can do short of letting all your friends know not to open the emails. You can then (if you wish) create another hotmail account, and use that one exclusively.
"So won’t you give this man his wings
What a shame
To have to beg you to see
We’re not all the same
What a shame" - Shinedown