When you are told to update software, you should consider the source. Microsoft always distributes software via CD-ROM or the Internet, they do not email patches to users.
Recently there have been several email messages going around the Internet which falsely claim to come to from Microsoft and requests the user apply an attached patch.
Do not do this.
When ever you have a question about the validity of a patch, go to the software manufacturer's site. For instance, todays MS home page includes a link to this page explaining the MS update distribution policy described above.
And if someone mails you directions to fix a "virus", please check it out first at your virus checker software manufacture's page. See our previous article called Hoaxes are Bad, or maybe for a lighter look at the issue, the VMyth.com site.