Microsoft has modified the way Windows 10 handles the operation of disconnecting a USB or Thunderbolt storage device. This includes USB thumb drives, external hard drives, flash drives, and even USB data transfer connections established between PCs and smartphones.
The change took effect with the wide deployment of Windows 10 version 1809, the October 2018 Update.
Until now, the default policy in all previous Windows versions when disconnecting a USB storage device was the "Better performance" setting.
Starting with Windows 10 v1809, this became "Quick removal." The difference between the two is significant.
"Better performance" means that Windows manages data transfers and storage operations in a manner that improves performance. This includes caching data while it's being transferred, opened, or in preparation for certain operations.
This constant readiness on Windows' part meant that any user who wanted to disconnect a USB or Thunderbolt-connected storage device had to go through the "Safely Remove Hardware" process, which meant triggering a manual Eject.
All Windows users know the procedure.
But with Windows 10 v1809, the default state for all USB and Thunderbolt storage devices has become "Quick removal," which is a state where external storage devices can be disconnected without following the "Safely Remove Hardware" process.
But there are inconveniences to switching to "Quick removal" as the default setting. The first is that Windows won't cache disk writes anymore, meaning that data moved to an external storage device might take longer to transfer.
Microsoft will allow users to overwrite the default "Quick removal" state on a per-device basis.
This is for users who are copying backups to external hard drives or those copying crucial PowerPoint slides or other business documents to a USB memory stick and may want to make sure data transfers both safely, faster, and without any potential problems .
The procedure is as follows, but users need to be aware that once a USB/Thunderbolt storage device is set back to "Better performance," they will also need to follow the "Safely Remove Hardware" process.
6. Select Policies, and then select the policy you want to use.
Additional info in this Microsoft KB article.
Correction: An earlier version of this article stated that the change will come into effect with the upcoming May 2019 Update. That was incorrect. The change was made in the October 2018 Update, which Microsoft has recently designated for broad deployment.