Windows performance

Windows startup stuck on checking disk (chkdsk)

Windows sometimes runs an automatic disk check at startup after an improper shutdown or detected error, and on a large or aging drive this can take a long time and make startup feel stuck.

Difficulty
Easy
Time
30 minutes-several hours
DIY cost
$0
Pro cost
$80–$150

Symptoms

  • Startup shows a screen about checking or repairing a drive
  • Progress percentage seems to move very slowly
  • This started after a power loss or forced shutdown
  • The PC eventually finishes and boots normally

Likely causes

  • CommonAn improper shutdown (power loss, forced restart) triggering an automatic checkWindows checks the drive for consistency after an unclean shutdown.
  • CommonErrors detected on the drive during a previous scanWindows schedules a deeper check when it suspects file system issues.
  • CommonA large or slow (mechanical) drive taking a long time to scan fullyMore data and slower read speeds both extend scan time.
  • PossibleActual bad sectors or file system corruption needing repairThis is exactly what chkdsk is designed to find and fix.
  • PossibleA failing drive causing the check to stall or restart repeatedlyIn rare cases, a failing drive can make chkdsk itself struggle to complete.

What to do

  1. Let the check run to completion at least once; interrupting it can leave the file system in a worse state.
  2. If it seems frozen at the same percentage for hours, note that some stages (like reading the full drive) can appear stuck while actually working.
  3. If it's genuinely frozen for many hours with disk activity light off, you can force a restart as a last resort, understanding this carries some risk.
  4. Once Windows boots successfully after the check, back up your important files as a precaution.
  5. Check the drive's health using the manufacturer's diagnostic tool or Settings > System > Storage.
  6. If the check reported and fixed errors, monitor for recurrence, since repeated chkdsk triggers can indicate a failing drive.
  7. Ensure the PC has reliable power (avoid unclean shutdowns going forward, use a UPS if outages are common) to reduce future triggers.
  8. If chkdsk keeps running at every boot without resolving the issue, that's a sign to have the drive professionally evaluated.

Tools and parts

  • None required

When to call a pro

If chkdsk repeatedly fails to complete or the drive shows signs of failure afterward, back up your data immediately and have a professional assess or replace the drive.

Safety

Generally low risk

Generally low risk for a careful person. Stop if anything looks different from what this guide describes.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.