It looks like Microsoft will be releasing four security updates on Tuesday, including two that are critical and are affecting Windows Internet Explorer 7, Windows XP Professional Edition, Windows Vista, Microsoft Exchange 2000 Server, Exchange Server 2003 and Exchange Server 2007, the company announced on Thursday.

Furthermore, two other updates rated important affect SQL Server 200, SQL Server 2005 and Microsoft Office. As expected, these vulnerabilities could allow an attacker to remotely execute cod on an unpatched system. As usual, Microsoft will release the security updates on Patch Tuesday, the second Tuesday of the month.

However, even if the company provides advance notification for customers to alert them as to the software affected, it keeps the details vague in order to prevent exploits from being developed by hackers, which is a normal decision.

In related news, it looks like Windows Vista is Microsoft’s least popular OS, even if the company expected it to be twice as popular as XP. More than two yearsafter its launch, Vista has only managed a penetration of just 9 percent, giving it the dubious distinction of being the least popular new Windows OS out of the gate, ever.

It remains to be seen if Windows 7 will make up for Vista’s mistakes, and that’s because Microsoft is sure hoping for that to happen as quickly as possible. Among Microsoft users, 71 percent still use Windows XP, 10 percent use Windows 2000, 9 percent use Vista, Apple’s Mac OS X and other each garner 3 percent, and 2 percent use Linux.