So you had your Windows XP 32-bit computer working. Everything was fine. You do updates like… So you had your Windows XP 32-bit computer working. Everything was fine. You do updates like you should, and you put off upgrading to Vista or Windows 7 because you want to give Microsoft a little while longer to work all the kinks out of it. Excellent. Your machine should work just fine.

Unless you download and install update KB977165 in response to security bulletin MS10-015.

A tall order, because the update did not show any real sign of trouble before most people downloaded it. According to ComputerWorld.com, however, many Windows XP 32-bit customers had their systems crippled by the unassuming MS10-015 update.

According to the article, a support ticket was opened by a user who, immediately after installing the update, discovered that his computer no longer wanted to boot beyond a blue screen.

The blue screen cited vague problems that could cause damage to your computer, and caused the system to reboot long before it got to the main Windows screen.

After the initial complaint, other users echoed, citing constant reboots and blue screens as side effects of the only thing on their system that had changed — the installation of a Microsoft update.

The forum received responses from both official Microsoft employees and those who appeared to claim they were Microsoft employees but without confirmation.

Microsoft’s response so far has been to downplay the problem’s impact and suggest that users who have not yet installed the update pack refrain from doing so until more information on the errors can be found.

Jerry Bryant, the senior security communications manager lead of the Microsoft Security Response Center, wrote on his blog that the problems affected a “limited number” of XP users, but that it was serious enough for users to stop offering the patch automatically over Windows Update. He described the core vulnerability as a method by which an attacker could gain “privileged access” to a system without the proper password.

A Microsoft moderator on the forum responded by providing instructions for the Microsoft restoration utility, available on any Windows XP installation CD. The restoration utility could be run in order to restore core system files changed by the problematic update.

But Microsoft officials want to remind users that the update fixed serious security vulnerabilities and that “rolling back” a system using the restoration utility leaves the system functional but vulnerable.

The better way to go, according to Jerry Bryant, is a workaround to disable a Windows subsystem known as the “NTVDM.” Disabling this subsystem will prevent the vulnerability from allowing unauthorized users from gaining access to an XP system.

ComputerWorld.com stated that the update patched an old bug that leaves all 32-bit Windows machines vulnerable to attack. Apparently the attack is 17 years old and was made public by an employee of Google who successfully exploited, then published, the bug.

The problematic patch came in a pack of patches for both Windows and Internet Explorer.

Microsoft experienced similar problems before; previous updates have been known to cause significant problems with versions of Windows.

Most notably, users of Windows XP who tried to upgrade to Service Pack 3, and some users of Windows Vista who installed a previous update, found themselves in infinite reboot loops, effectively making their systems useless.

If you are running a Windows XP 64-bit machine, you have nothing to worry about. It seems, in fact, the security vulnerability at the center of this problem does not even exist in the 64-bit kernel.

Similarly, users of Windows Vista and Windows 7 do not need to worry about the update. Installing the update on newer systems does not seem to result in any ill effects.