The Windows 10 April 2018 Update, version 1803, is enjoying the fastest rollout of any Windows 10 major update thus far.

Even though last-minute delays pushed its rollout into May for most users (it was available to manually install on the last day of April, but it didn't hit Windows Update until May's Patch Tuesday), as of the 29th of the month, it's now being used on just over half of all Windows 10 machines.

By way of comparison, the previous update, version 1709 ("Fall Creators Update") took about two months to reach 50 percent penetration, and the one before that, version 1703 ("Creators Update") took around three months to reach the same level.

The faster rollout suggests greater confidence within Microsoft that the update is relatively problem-free. Version 1803 hasn't been immune to issues—it was blocked temporarily from installation on systems with certain SSDs—but the speed of the rollout suggests that it has avoided any major issues.

The penetration figures come not from Microsoft but from AdDuplex, which offers an advertising SDK that is used in UWP applications. This means that certain kinds of installations—those using the Long Term Servicing Channel (LTSC) releases, which don't include the Microsoft Store at all—are not included. Other installations—those in corporate environments—are likely undersampled due to lesser use of ad-supported software. Microsoft hasn't released numbers, but it maintains that deployments of the LTSC release are relatively limited. We'd expect enterprise adoption to have a longer tail—greater use of older versions to take advantage of the 18-month support window that each update receives—and slower initial adoption.

We still hear quite a bit of trepidation from enterprises about the new updates, especially with regard to their quality during the first few months of availability. This doesn't seem to be sufficient to drive enterprises onto the LTSC releases, but it does mean that they're not willing to be part of the initial stampede of updates. The release of each update is staggered, with Microsoft offering it to a wider range of systems as more data is received about how well it's working. In the past, the company has announced when it has opened the floodgates and made the update available to everyone; it has also said that this action is the cue for wider corporate deployments. We'd expect this to remain true for version 1803.