Windows & BSOD · medium

How to fix0x80070070

0x80070070 - Disk Full Update Error

What this error means

There is not enough available storage for this update operation (0x80070070). Free space on the relevant drive and retry the same update.

Applies to
Windows 11; Windows 10 interfaces may differ
Difficulty
Beginner to intermediate
Before changes
Some checks require restart or system changes

Documentation checked: 2026-09-28 · Editorial guide checked against the linked documentation; not tested on every hardware configuration.

Before you begin

Back up important files. Save your work and record the exact message before changing anything. If Windows cannot start, see the startup guide.

Work through these checks

0 of 4 complete
01Check which drive is short of space
  1. Open File Explorer → This PC and inspect the free space on the Windows drive.
  2. Read the update prompt for the amount or location of space it requires.
What to expect

You know which drive needs attention.

If it does not help

If the prompt concerns a different partition, do not resize partitions without specific guidance.

Browse related errors
02Review cleanup recommendations
  1. Open Settings → System → Storage → Cleanup recommendations.
  2. Inspect each proposed deletion before selecting it. Move important personal files to a verified backup instead of deleting them.

Removing previous Windows installation files can remove rollback options. Do not select Downloads or other personal data without reviewing it.

What to expect

The available space increases after removing items you no longer need.

If it does not help

If space remains low, inspect large installed applications and personal files.

Browse related errors
03Retry the update
  1. Return to Windows Update after cleanup.
  2. If Windows offers an external-storage option for the update, follow its on-screen instructions and keep that drive connected as requested.
Windows Update reports it needs more space and offers internal cleanup or external storage.
Example Windows 10 dialog. Microsoft Support: Free up space for Windows updates. Your version may look different.
What to expect

The update can proceed with the required working space.

If it does not help

Record the remaining storage requirement if it still cannot continue.

Browse related errors
04Prepare a focused support request
  1. Collect the KB number, Windows build, failure time, and checks already tried.
  2. Use the support link for that specific update or contact your organisation’s IT team if the computer is managed. Share logs privately only after checking them for personal data.
What to expect

Support can distinguish this incident from unrelated failures with the same numeric code.

If it does not help

Keep the backup and the original error details; avoid undocumented registry or partition changes.

Browse related errors

Possible causes

  • Low physical storage capacity on system drive C:
  • Excessive update backup files (Windows.old directory)
  • Temporary folder clutter and download cache files
  • Too small system reserve partition allocated

Useful Windows tools

These commands open Windows tools. Review changes before applying them.

cleanmgr.exe

Sources & further reading