Security News > 2021 > March > Windows 10 ISO installs may fail to replace Microsoft Edge Legacy
Microsoft has addressed a known issue causing the new Microsoft Edge web browser not to install from custom Windows 10 installation media including updates released on Thursday, March 25.
Microsoft Edge Legacy is also being removed if using Windows 10 install media bundling the KB5000850 non-security release preview update for Windows 10 1909 and Windows Server 1909.
"Devices with Windows installations created from custom offline media or custom ISO image might have Microsoft Edge Legacy removed by this update, but not automatically replaced by the new Microsoft Edge," Microsoft explains.
The new Chromium-based Edge is the default Windows 10 web browser after replacing Edge Legacy, starting with Windows 10 Insider Preview Build 21313.
Edge Legacy will be permanently replaced in all Windows 10 builds by the new Microsoft Edge on all systems after installing April's Windows 10 Patch Tuesday security update.
In November 2019, Microsoft also fixed an issue triggered by managed Windows 10 systems being updated from outdated installation media and causing Windows 10 certificates to disappear.
News URL
Related news
- Microsoft silently fixes Start menu bug affecting Windows 10 PCs (source)
- Microsoft will update Office apps on Windows 10 until 2028 (source)
- Microsoft confirms May Windows 10 updates trigger BitLocker recovery (source)
- Windows 10 KB5055518 update fixes random text when printing (source)
- Microsoft: Windows CLFS zero-day exploited by ransomware gang (source)
- Microsoft fixes actively exploited Windows CLFS zero-day (CVE-2025-29824) (source)
- Microsoft fixes auth issues on Windows Server, Windows 11 24H2 (source)
- Bad luck, Windows 10 users. No fix yet for ransomware-exploited bug (source)
- Microsoft Patches 125 Flaws Including Actively Exploited Windows CLFS Vulnerability (source)
- Microsoft: April 2025 updates break Windows Hello on some PCs (source)