Microsoft this week confirmed and then fixed a widespread bug in the Windows 8 Release Preview. The bug, which I first reported last month, causes PCs based on newer Intel chipsets to freeze on a seemingly random basis, and once it happens, there’s no recourse but a hard reset of the machine. And although some seem to misunderstand the severity of this bug, kudos to Microsoft for fixing a bug in an OS that isn’t even aimed at production environments.

I first reported this—and one other bug in the Windows 8 Release Preview—on June 22. The purpose of the report, "Broken Windows? Two Serious Issues that Make Windows 8 Release Preview Almost Unusable (For Me)," was to gather reader feedback that I could forward to Microsoft if the issues proved widespread. Thanks to more than 500 email confirmations, I was able to quickly inform the software giant that I wasn’t imagining these issues, and that both issues were quite common indeed.

Microsoft told me that it hadn’t seen either issue in its feedback telemetry but would continue investigating. A source at the software giant confirmed for me that the first of the two bugs, the hanging issue, was indeed quite common and that it had been fixed in internal builds newer than the Release Preview. The source provided me with a specific workaround but asked that I not publish it because it could have an adverse impact on battery life, and the company was investigating potential side effects and whether to publish a formal fix.

(Based on reader feedback, I did publish a workaround of my own in "Broken No More? A Windows 8 Release Preview Freeze Workaround." This workaround, which involves installing Hyper-V, appears to affect the same Intel drivers that caused the initial bug. And while it’s not perfect, it does cut down on the hanging issue dramatically.)

On Monday, however, Microsoft quietly published the internal workaround I was forwarded in June; I assume it was found to be relatively safe. (You can find out more in the Microsoft support article "Multimedia or communication activities may cause a computer that is running Windows 8 Release Preview or Windows Server 2012 Release Candidate to stop responding.") And on Tuesday, Microsoft published its formal software fix through Windows Update. Given the severity and regularity of this bug, all users of the Windows 8 Release Preview should update their PCs immediately.

The hanging bug has been incorrectly described as “rare” by some commentators (even by those who have experienced it repeatedly), but it’s anything but rare: It affects every PC based on an Intel “Sandy Bridge” or “Ivy Bridge” Core chipset, according to Microsoft’s internal documentation. So it most certainly affected many thousands of people who were testing the Windows 8 Release Preview. Microsoft should be commended for fixing a bug for users of a system that isn’t even designed for production environments. But after all, Windows 8 is the most tested pre-release software ever, based on download numbers for pre-release versions of the OS. It was the right thing to do.

As for that second bug, which involves network file transfers, it’s intermittent and even harder to pin down than the hang bug. I’ll report back if I hear anything about a workaround or fix.