A security update that Microsoft pushed out earlier this week crashes some Windows 7, Windows Server 2008 and Windows Vista machines, forcing them into an endless cycle of reboots that can only be stopped by repairing the operating systems.

Microsoft recommends that all Windows 7 users uninstall the security update.

The update came as a part of Patch Tuesday, Microsoft's longstanding tradition of releasing security patches on the second Tuesday of each month. The main vulnerability that this month's update addressed required a would-be hacker to possess valid login credentials and physically interact with a computer. Although this issue was not critical by itself, some of the other problems that Patch Tuesday addressed were.

The results of the patch created even more trouble. Upon restarting their machines, many users found that Windows would not start, defaulting instead to the infamous blue screen of death. Error messages varied, but users typically saw "The file system structure on the disk is corrupt and unusable," "The Session Manager Initialization system process terminated unexpectedly," or "Windows failed to start."

Microsoft has found a link between the flawed update and antivirus programs from Kaspersky Labs, which specializes in computer security products. Neither company has explained the relationship between Kaspersky's program and the security update, but Kaspersky has issued a statement to its users.

"Kaspersky Lab apologizes for any inconvenience this has caused our customers," the company statement said. "The company will work harder to strengthen its technical collaboration with its partners in order to prevent any repeat of this incident in the future."

PC owners who have already installed the software and have not yet restarted their machines are in luck, as Microsoft has provided a method for uninstalling the update. Two of the options involve messing around with the sometimes-complicated command prompt, but less tech-savvy users can simply uninstall the update by clicking on Control Panel, Programs and View Installed Updates.

Users who have already tried unsuccessfully to restart their machines may have significantly more trouble. The Windows 7 installation DVD or a bootable USB stick will give users the option of a System Restore, which should do the trick. If that doesn’t work, they will have to dive into the command prompt and remove the offending software update manually. [See also: 7 Ways to Protect Your Computer's Data]

The botched security update has not affected everyone. If you've installed the update and haven't experienced crippling shutdowns, you're probably in the clear, but you can still uninstall it to be on the safe side.

Microsoft has ceased distribution of the patch and will provide a fix as soon as possible. The company has also confirmed that the issue, though potentially very irritating, cannot delete or compromise existing data in any way.

Just about everyone has, at one point or another, tried to fix a minor problem and ended up creating a much worse one in the process. Microsoft's faux pas is just more visible than most.