Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

You’re trying to install a Windows update manually—maybe a cumulative update or a .cab file—and y...

You might see a version mismatch warning when opening Windows Defender Security Center or running...

After upgrading Windows—whether from an older version or a feature update—you might see an error ...

You see the error "Windows Security service failed to start" with code 0x80070422. This usually m...

When trying to activate Windows 10, you might see an error like "We can't activate Windows on...

How to Fix Windows Activation Proxy Error
If you see "We can't activate Windows on this device because of a proxy error" or similar, your s...