Give it 30 minutes on a stable connection first. Then turn off Metered connection, disconnect VPNs, restart the PC, run the Windows Update troubleshooter, and if it's still stuck, clear the SoftwareDistribution download cache (commands below).

The short explanation

Updates sometimes sit at 0% while Windows prepares or checks them. Large feature updates can look stalled for a while. A real stall typically traces back to the network (metered connection, VPN, proxy), the BITS download service, or a corrupted partial download in the cache.

Symptoms

  • “Downloading - 0%” or “Pending download” for hours.
  • Progress stops at the same percentage.
  • Other updates queue up behind it.

What causes it

  • Metered connection or Delivery Optimization limits.
  • VPN or proxy interfering.
  • Stuck BITS or Windows Update services.
  • Corrupted partial download in SoftwareDistribution.

Try these fixes

  1. Wait and check activityLeave it 30–60 minutes. In Task Manager, watch Network activity for 'Service Host: Delivery Optimization' or 'Windows Update'.
  2. Check metered connectionSettings → Network & internet → Wi-Fi/Ethernet → your network: turn off Metered connection. In Windows Update → Advanced options, turn on Download updates over metered connections only if your data plan allows.
  3. Disconnect VPN and restartTurn off VPN apps and restart the PC (not shut down).
  4. Run the troubleshooterLet Windows check itself first: Settings → System → Troubleshoot → Other troubleshooters → Windows Update. Windows 10: Settings → Update & Security → Troubleshoot → Additional troubleshooters.
  5. Clear the download cacheRun the commands below, restart and check for updates.

Command

net stop wuauserv
net stop bits
net stop cryptsvc
ren %systemroot%\SoftwareDistribution SoftwareDistribution.old
ren %systemroot%\System32\catroot2 catroot2.old
net start cryptsvc
net start bits
net start wuauserv

Run each line in an elevated Command Prompt (Run as administrator). Renaming these folders only clears the update download cache; Windows rebuilds them. If a rename says 'access denied', restart and run the lines again.

Check it's fixed: The download percentage starts rising within a few minutes of checking for updates.

Avoiding it in future

Install updates on a stable, unmetered connection and leave enough free disk space (20 GB+ for feature updates).