Why wont windows live messenger show ?!!??!

hey ,

Okay so about a week ago we had a huge lightening storm which blew out our computer. so we finally just took it into the computer guy and he "fixed" it. BUT he deleted everything on it, and esspessically my favourite.. WINDOWS LIVE MESSENGER , he replaced it with the OLD OLD school msn , which lemme tell you sucks:(

So anyway, i thought i could just download it back. but i was wrong. i went to the site and it started to download but then everytime it was half way through the download my computer would shut off. so i just kept doing it and it just kept shuting off, untill FINALLY it said it successfully downloaded... so i went to my desktop and there was still just MSN, and so i looked at my start menu and still what do you know .. OLD SCHOOL MSN.

now everytime i try and download it again, it says its already downloaded. :s .. when really its actually not.

im very confused and frustrated, and all i want it the normal windows live messenger back.

......... PLEASE HELP ME.