Hi,
don't worry your computer is not infected. From time to time I also get an e-mails like these one. Just mark them as spam and they won't show up in your inbox again. There might be several reasons why you get such an e-mails. I think spammers generates lots of login names and you have a similar login with those generated. It's only matter of time when hotmail team will notice these e-mails and will block the spammers.