Microsoft was forced to halt the rollout of Meltdown and Spectre CPU fixes on Tuesday after its updates caused some PCs to become unbootable. The software giant blames the hiccup on AMD and says it is working with the company to resolve the problem.

As if the Meltdown and Spectre issues weren’t bad enough already, Microsoft rolled out a “fix” this week that ensured some computers would no longer be affected by them because they were unable to boot up. The problem is specifically related to machines with AMD CPUs.

Microsoft blames AMD

Microsoft blames AMD’s documentation for the embarrassing mistake.

“Microsoft has reports of customers with some AMD devices getting into an unbootable state after installing recent Windows operating system security updates,” reads a Microsoft support document.

“After investigating, Microsoft has determined that some AMD chipsets do not conform to the documentation previously provided to Microsoft to develop the Windows operating system mitigations to protect against the chipset vulnerabilities known as Spectre and Meltdown.”

Microsoft has now blocked AMD computers from receiving updates temporarily so that additional users won’t be plagued by the flaw. It says it is working with AMD to resolve the problem and will resume issuing CPU fixes for AMD machines soon.

How to fix boot problems

In its support update, Microsoft points to a number of guides that could help AMD users return to a bootable state. None of them recommend that you ditch your Windows PC and buy a Mac.