It is available from Windows Update now or from the following links below. If you use the internet or receive email with a client that displays images, you probably want this patch.
http://www.microsoft.com/technet/security/Bulletin/ms06-001.mspx
Downloads:
XP
http://www.microsoft.com/downloads/details.aspx?familyid=0c1b4c96-57ae-499e-b89b-215b7bb4d8e9
Server 2003
http://www.microsoft.com/downloads/details.aspx?FamilyID=1584aae0-51ce-47d6-9a03-db5b9077f1f2
2000
http://www.microsoft.com/downloads/details.aspx?FamilyID=aa9e27bd-cb9a-4ef1-92a3-00ffe7b2ac74
XP x64
http://www.microsoft.com/downloads/details.aspx?familyid=3a1166e6-5e9e-4e73-bcd4-28eca6ece877
Windows Server x64
http://www.microsoft.com/downloads/details.aspx?familyid=a8f4dcba-5d28-4d9d-a6a4-3b71108cfe2d
