Windows 8.1 is Microsoft’s attempt to address some of the complaints users have voiced in the year Windows 8 has been available. Even if it’s bringing the people what they want, it might also come with a few unwanted bonuses, like baffling and cryptic boot errors that turn some Surface RT units into bricks. That’s been happening to enough users that Microsoft has now pulled the Windows RT 8.1 update while it investigates the issue.Machines affected by the error would fail to boot after updating, instead bringing users to a recovery screen that informs them the PC needs to be repaired due to missing Boot Configuration Data. The error goes on to suggest the recovery tools on installation media (like a DVD or USB key) would be needed to fix the issue. Of course, most PCs no longer come with such things.Microsoft officially announced the removal of the RT 8.1 update on the Microsoft Answers site over the weekend. The statement doesn’t include any kind of timeline for returning the RT 8.1 update to the store. However, anyone that already installed the update successfully should be in the clear — this is simply a measure to limit the scope of the damage while Redmond sorts out the problem.Those bitten by the bug are not without recourse. A fix has been found that can solve the boot issue without destroying any data. It requires a Windows RT recovery USB drive, which can be made on another Windows PC. Using the troubleshooting tools on the recovery drive will enable you to repair the boot files and finish the upgrade. Make sure to check out the detailed instructions before attempting this, though.