Figuring out when to install the Windows 10 May 2019 Update has been a bit of a crapshoot. Microsoft is automatically notifying some people about the update's availability. But it's also blocking others from installing the update because it believes their systems aren't ready, and Windows Latest reported on July 28 that an outdated Intel Rapid Storage Technology (RST) driver prevents the update from installing.
That's partly by design: Microsoft said in a support article that the Windows 10 May 2019 Update requires Intel RST version 126.96.36.1994 or later to function. Microsoft recommends the 188.8.131.524 release but didn't explain why. Attempting to install the latest major Windows 10 update without a compatible version of the Intel RST leads to a warning that the outdated driver causes stability problems on Windows.
It makes sense that using a driver older than what Microsoft recommends would cause stability issues. The problem is that people are receiving the same warning from Windows Update even after they install a compatible version of the Intel RST driver.
Windows Latest found numerous discussion threads on Reddit, Twitter, Microsoft's answer forum and its own comment section backing up these claims. It seems that for some reason Windows Update can't detect the new Intel RST driver after installation, which kind of defeats the purpose of updating the drivers. It's like forgetting a gym card, retrieving it and then still being denied entry to the building.
This isn't a great look for the Windows 10 May 2019 Update, the release of which had been relatively tame compared to the Windows 10 October 2018 Update. Hopefully the problem with Windows Update not recognizing the new Intel RST driver is resolved soon, especially since Microsoft is now pushing the most recent Windows 10 release on people still running the Windows 10 April 2018 Update.