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Windows errors and troubleshooting

Find Windows update, startup, device and recovery guides. Match the Windows build and KB number before applying advice for a specific known issue.

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Related guides 54

▦WindowsResolved

PC Reset or Recovery Fails After KB5063875

Settings > System > Recovery > Reset this PC fails

Windows 11 23H2/22H2 (Targeted by KB5066189 in this record. The same symptoms were also reported in other Windows 10 and LTSC editions, but the corrective update to be applied differs depending on the OS)KB5063875
Checked 2026.09.05Read guide ↗
▦WindowsResolved

Microsoft Changjie IME Input Fails After KB5062552

Unable to create or select a word after entering a complete character structure

Windows 11 23H2 and Windows 11 22H2 Enterprise/Education after KB5062552. The KB5062663 preview fix is listed for 23H2; do not install that package on 22H2 or another Windows version.KB5062552
Checked 2026.09.06Read guide ↗
▦Microsoft Defender Antivirus on WindowsInvestigating

False “Microsoft Defender Antivirus Is Disabled” Notification

"Microsoft Defender Antivirus is turned off" notification appears when starting or using Windows

Windows 11 26H1/25H2/24H2/23H2, Windows 10 22H2/21H2/LTSC 2019/LTSC 2016, and Windows Server 2025/2022/2019/2016/2012 R2/2012 with the latest Defender updates
Checked 2026.09.05Read guide ↗
▦Windows 11 / .NET Framework 3.5Troubleshooting guide

Enabling .NET Framework 3.5 fails with 0x800F081F

.NET Framework 3.5 cannot be enabled in Windows Features

Windows 11 25H2 and earlier. Windows 11 26H1 (build 28000) and later use a standalone installation method and are outside this scope0x800F081F
Checked 2026.09.05Read guide ↗