Windows 8 build 8520

Windows 8 build 8520 is a build of Windows 8, which was first uploaded to BetaArchive on 3 February 2020 in the x86 and ARM32 architectures in the Czech and Traditional Chinese (Hong Kong SAR variant) languages respectively; the American English and Arabic language versions of this build were later uploaded to the BetaWiki Discord server on 4 May 2022 under the ARM32 architecture. It is the last build of Windows 8 to include its predecessor's logon background as the default wallpaper.

This build was released to Microsoft partners through the Ecosystem Engineering Access Program (EEAP) and as is common for such builds coming from the  branch, it had most inbox applications stripped out at compile time.

Changes

 * Reverted the set of wallpapers to the ones included in earlier builds.
 * The Start screen backgrounds seen in the RTM release have been introduced.

Bugs and quirks
In the Czech version, the Microsoft Confidential watermark appears to be pseudo-localized and in English.

TimeBomb
This build contains a broken timebomb and as a result can be installed on the current date.