Windows diagnostics · free & local

Diagnose a Windows error

Understand the message. Choose a safe check. Keep the evidence.

Try a scenario

Resume a saved session — paste a Resume Capsule

The capsule is validated and restored only in this browser. An invalid capsule changes nothing.

Evidence before repair

One bounded loop — never an open-ended repair chain.

Identify

Paste the exact error. The result separates what Windows confirmed from what it does not prove.
Check

One read-only or reversible check, with the expected result, how to verify it, and the rollback.
Record

What the check produced — and separately, whether the original problem came back.
Decide

Stop and monitor, repeat once, record one missing fact, or escalate with the Evidence Pack.

Deliberately excluded: driver updaters, registry cleaners, dump uploads, and uncontrolled AI repair commands. Read the risk policy and review method.

Go straight to a focused route

Diagnostic routes

Error CheckerRecognize a code, exact message, driver filename, Stop Code, or command result and route it to the right diagnostic family. UpdateSeparate download, install, restart, servicing, space, connectivity, and upgrade rollback evidence. DeviceInterpret Device Manager status only after identifying the affected device category. BSODIdentify the confirmed bug-check family, capture recurrence context, and collect usable crash evidence without guessing a root cause. Command OutputParse the final SFC or DISM status locally and show the next evidence checkpoint before any administrator repair step. Driver filesIdentify what a named .sys file can establish—and what it cannot establish—before changing drivers or security software. Network & proxyDistinguish browser-only, proxy, VPN, DNS, and managed-network evidence without defaulting to destructive network resets. Windows SandboxCheck edition, Windows feature state, virtualization, hypervisor, and policy context before changing configuration.

Evidence readers

Event ViewerEvidence readerPaste one time-matched Event Viewer record as rendered text or XML and extract the provider, Event ID, time, level, faulting fields, and diagnostic tokens without uploading the event. Update / CBS logEvidence readerPaste a short WindowsUpdate.log, CBS.log, DISM, or servicing excerpt and extract timestamps, components, KBs, packages, error codes, and repeated error clusters without uploading the log. System informationEvidence readerPaste a bounded msinfo32 or DxDiag text report and extract the Windows build, system model, firmware mode, memory, DirectX, display-driver, and explicitly reported problem-device facts without uploading the report. Driver identityEvidence readerPaste bounded driverquery or PnPUtil enumeration text and extract driver, package, provider, class, version, signer, state, path, and device-relation facts without recommending a download or naming a culprit. Known issuesEvidence readerEnter a Windows version/build, installed KB, and exact symptom to compare them with a bounded, dated Microsoft Release Health snapshot without claiming that a matching record proves this device is affected.