Microsoft has announced plans to issue four "critical" security bulletins next week that address vulnerabilities in Windows, Internet Explorer, Outlook Express and Windows Mail in Vista. "Critical" is the most severe ranking Microsoft assigns to security flaws, which typically indicates a system can be compromised remotely with little interaction required by the user. Specifically, Windows XP Service Pack 2, Windows Server 2003, IE 5.01 running on Windows 2000 with SP4 and Windows Mail in Vista are among the affected software. There are six bulletins in total according to Microsoft"s advance advisory notification, all of which will be released next Tuesday as part of Microsoft"s monthly "Patch Tuesday" ritual.