Use Windows Recovery Environment, Startup Repair, Safe Mode, boot configuration tools, and supported recovery options to diagnose a Windows 10 computer that will not start.
Follow the Windows recovery steps yourself, or use Advanced PC Repairs when Windows can still start and you want help identifying supported system conditions.
Manual recovery
Automatic-assisted option
If Windows can still start, install Advanced PC Repairs and scan for supported Windows conditions related to system files, stability, and performance.
Startup Repair is a built-in Windows recovery tool that runs from Windows Recovery Environment, also called WinRE. It checks for certain problems that can prevent Windows from loading, including damaged system files and errors in the boot configuration. When it finds a supported problem, it attempts a repair and records the outcome.
Startup Repair is useful when the computer reaches the manufacturer logo but Windows does not finish loading, returns to recovery repeatedly, shows a boot configuration error, or begins failing immediately after a system change. It is not a complete hardware diagnostic and cannot fix every failed drive, defective memory module, firmware problem, encryption issue, or incompatible driver.
Photograph any error code and note whether the failure began after an update, driver, application, power loss, firmware change, or new hardware.
Shut down and remove recently connected USB storage, docks, printers, or other nonessential peripherals. Keep the display, keyboard, mouse, and system drive connected.
Encrypted devices can require the recovery key before WinRE will unlock the Windows drive. Do not proceed into advanced recovery without access to the correct key.
If the computer cannot detect its system drive, overheats, loses power, or reports a manufacturer diagnostic failure, investigate that condition before repeatedly repairing Windows.
| Situation | How to open WinRE |
|---|---|
| Windows still opens | Open Settings → Update & Security → Recovery → Advanced startup → Restart now. |
| You can reach the sign-in screen | Hold Shift while choosing Power → Restart. |
| Windows repeatedly fails to start | Allow Automatic Repair to appear, then choose Advanced options. Avoid repeatedly interrupting power unless Windows cannot reach recovery by another supported method. |
| The internal recovery environment is unavailable | Boot from official Windows installation media and choose Repair your computer instead of Install now. |
From the Choose an option screen in WinRE, select Troubleshoot.
Select Advanced options, then choose Startup Repair.
Choose the Windows installation you want to repair. Enter the BitLocker key or account credentials when required.
Do not cut power while Startup Repair is working. Windows will restart if it completes a repair or show that it could not repair the PC.
If Windows opens, back up important files, install supported updates, and review the change that caused the original failure.
Do not run the same repair indefinitely. Return to Advanced options and select the next evidence-based recovery method.
| What happened before the failure? | Best next option | Why |
|---|---|---|
| A Windows update was installed | Uninstall Updates | Removes the most recent quality or feature update when it aligns with the first failed boot. |
| A driver or application was added | Startup Settings → Safe Mode | Loads a reduced set of drivers and services so the recent change can be reversed. |
| System settings changed recently | System Restore | Returns system files and settings to a selected restore point without targeting personal documents. |
| Windows files may be damaged | Command Prompt or a supported repair install | Allows targeted offline checks or reinstallation after backups. |
| The drive is missing or reports errors | Manufacturer diagnostics and data backup | Startup Repair cannot restore a physically failing or undetected drive. |
In WinRE, choose Troubleshoot → Advanced options → Startup Settings → Restart. Select Safe Mode or Safe Mode with Networking only when networking is required. Once signed in, remove or roll back the single driver, application, or service that matches the failure timeline.
A stable Safe Mode session points toward a third-party driver, service, security filter, or startup application, but it is not proof of one specific culprit. Change one item at a time and test a normal restart.
If Windows can start normally or in Safe Mode, Microsoft recommends running Deployment Image Servicing and Management before System File Checker:
These commands repair supported Windows components and protected system files. They do not prove that the storage device, memory, firmware, or power system is healthy.
Manual boot repair is an advanced step for a confirmed boot configuration problem. Modern systems can use UEFI, GPT partitions, BitLocker, multiple operating systems, or manufacturer recovery layouts. A command copied for the wrong configuration can leave the computer less bootable.
BCDBoot can recreate boot environment files from an installed Windows directory. Bootrec is also available in WinRE for certain startup scenarios. Before using either tool, identify the correct Windows and system partitions, preserve the BitLocker key, and make a backup. If those details are unclear, use Startup Repair, System Restore, or qualified technical support instead of guessing drive letters.
On a working computer, use Microsoft’s official Windows 10 media tools to create installation media on an empty USB drive. Boot the affected PC from that drive and choose Repair your computer to access recovery tools. Confirm the edition, architecture, language, and boot mode before reinstalling.
Installation media is not the same as a manufacturer recovery drive. A manufacturer recovery process may restore bundled software or factory partitions and can erase files, so read its description before continuing.
If Startup Repair, update removal, Safe Mode, and System Restore do not resolve the failure, Windows recovery options include Reset this PC and reinstalling from official media. Back up files, document application licenses, confirm account access, save encryption keys, and disconnect unrelated external drives first.
“Keep my files” preserves personal files but removes applications and resets many settings. It is not a substitute for a backup and may still fail when the storage device or other hardware is defective.
| Situation | Recommended action | Avoid |
|---|---|---|
| Windows fails once, then starts | Back up files, record the event, and monitor. | Running destructive recovery immediately. |
| Windows repeatedly enters repair | Run Startup Repair once, then use the failure timeline to choose the next WinRE tool. | Endless forced restarts. |
| Failure began after an update | Use Uninstall Updates or System Restore. | Changing unrelated drivers and partitions. |
| Safe Mode works | Reverse the most relevant recent driver, service, or application change. | Removing several components at once. |
| Drive is missing or unhealthy | Stop, protect data, and run manufacturer diagnostics. | Repeated writes or partition changes. |
| All repair options fail | Back up data, verify hardware, then reset or reinstall from official media. | Reinstalling before checking a failing drive. |
It diagnoses and attempts to repair certain startup problems, including damaged system files and boot configuration errors. It cannot fix every hardware, storage, encryption, or driver failure.
It is designed to repair startup components rather than erase personal files. Back up important data whenever possible because the problem that caused the boot failure can still put files at risk.
Time varies with the device and problem. If it stops responding for an unusually long period, check for storage activity and hardware warnings before cutting power. Repeatedly running the same unsuccessful repair is not useful.
A repair loop can occur when Windows cannot correct the underlying boot, update, driver, storage, or hardware problem. Use Advanced options to examine the timeline instead of repeatedly selecting Continue.
Official installation media can provide access to WinRE when the internal recovery environment is unavailable. The repair still depends on the cause and the condition of the system drive.
If Windows can start normally or in Safe Mode, download Advanced PC Repairs to scan for supported Windows conditions that may contribute to errors, instability, or reduced performance.
Software installation is required. Scanning is free. Optional paid repairs or subscription plans are presented with pricing and renewal terms before purchase.