Windows 10 build 19603 (rs prerelease)

Windows 10 build 19603 (rs_prerelease) is the thirteenth Insider Preview build of Manganese, the 20H2 development semester of Windows as a service. This build was released to Windows Insiders in the Fast Ring on 8 April 2020.

New features and changes

 * File Explorer now has intergration with the Windows Subsystem for Linux. Selecting the Tux penguin will show you all of the distros that you have installed, while selecting one will take you to the root file system for the selected distro.
 * A new Storage Settings feature was added that gathers unused files and apps so that a device can be more efficiently cleaned. A new link named "Show cleanup recommendations" was also added to gather the unwanted content and then remove it by clicking on the cleanup button that appears on the page.
 * The icons for the Alarms & Clock, Calculator, Feedback Hub, Get Help, Microsoft Solitare Collection, People, Voice Recorder, and Weather apps were updated in this build.
 * Calculator now has the graphing mode that was made available for Windows Insiders as an app update in build 19546.
 * The Microsoft News app was introduced.
 * The Voice Recorder and the Weather apps now require updates to be downloaded before they can be started.

Manage Disks and Volumes
This build's official announcement contains a picture from the Storage Settings page, which depicts the new user cleanup recommendations. However, one of the "More storage settings" links at the bottom of the page also says "Manage Disks and Volumes," which would bring the Disk Management experience to Settings, but it wasn't present in the app itself yet. This experience wouldn't be first spotted on released builds until three months later, and it wouldn't be publicly announced until another month later, on Iron builds 20175.1000 and 20197 respectively.

Bugs

 * The update process to this build has a chance of hanging for extended periods of time.
 * The documents section in the privacy settings has a broken icon, and as such, a rectangle shows in its place.
 * Sticky Notes windows can't be moved around on the desktop. To workaround this bug, set focus to the app, and then press Alt. After that action is peformed, select the Move option on the menu that appears. This will allow the window to be moved around with either the arrow keys or the mouse.
 * App icons on the taskbar can sometimes encounter rendering issues, including defaulting to the  icon.
 * The battery icon on the lock screen is always showing levels that are close to empty, regardless of the actual battery levels.
 * If updating to this build from an older one, the IIS configuration will be reverted back to their default values. The IIS configuration should be backed up prior to installation and then after this build is installed, the configuration can be restored back to the desired custom settings.
 * Language packs have a chance of failing to install on this build. This effect is most prominent for any user who chooses to reset their PC - the language packs they had prior to upgrading would presist. If this bug is encountered, the most commonly seen effect is that some parts of the UI don't display in the user's preferred language.
 * Quickly switching between WSL distros using the built-in File Explorer intergration could cause a transient access error.