Microsoft has confirmed by way of a Windows Support advisory that Apple Mac users have been blocked from updating to Windows 10 version 1903.
According to the Windows Latest site the support page in question has been made difficult to find, courtesy of Microsoft blocking web crawlers from indexing the document. Whether this was deliberate or an error is currently unclear. What is clear though, is that users of older Mac devices will likely find that the Windows 10 May 2019 update will fail to install.
Older, in this instance, is being defined as Mac devices prior to 2012. However, Microsoft also admits that users of newer Mac devices could also find themselves facing the same Windows 10 update block if they are using outdated Boot Camp software.
Here’s what Microsoft has to say on the matter: “If you are trying to update to the May 2019 Feature Update for Windows 10 (Windows 10, version 1903), you may experience an update compatibility hold and receive the message, “Mac HAL Driver – machaldriver.sys: Your PC has a driver or service that isn’t ready for this version of Windows 10.”
Apparently the error is being caused by a “compatibility hold” that has been put in place for devices with a “MacHALDriver.sys dated September 24, 2011 01:57:09 or older in Windowssystem32drivers.”
Microsoft offers a workaround, of sorts, to the block. “Updating your Apple Boot Camp Windows Support Software drivers may allow you to update to Windows 10, version 1903,” it states, adding, “you may be able to check for updated Windows support software, in macOS, choose Apple menu > App Store, then install all available updates.”
While Microsoft says it is working on a resolution to the problem and gives an estimated delivery of this as “late July,” there may be other options worth a try. Lifehacker suggests, “If you’re not on macOS Mojave, it might be time to try giving that a shot. Or, if you’re daring, you can even try jumping up to macOS Catalina.” It also suggests using Microsoft’s Media Creation Tool to build a new .ISO and install a clean Boot Camp version of Windows 10 version 1902 instead. This latter suggestion advising that it “might cause more issues,” such as bricking the install altogether.
For those of a technical persuasion who like rolling their sleeves up and getting dirty, Lifehacker has one final suggestion: overwrite the old Mac HAL Driver with a new one obtained from an unofficial mirror source such as referenced in the Overclockers forum here.
It should go without saying, but I’ll say it anyway, that any of these workarounds are carried out with a risk of something going wrong and losing data as a result. If you really cannot wait until the end of the month for the Windows 10 May Update then make sure you have made full backups before proceeding.