Steam - Error writing to disk during installation

What is STEAM-DISK-WRITE-ERR?

STEAM-DISK-WRITE-ERR shows up as a medium-severity software runtime fault. Steam will abort installing or updating a game with a disk write error. Common triggers are insufficient permissions for Steam/steamapps folder and the antivirus program blocks the writing of files. See the troubleshooting steps below for the fix.

Common Causes

• The Steam folder is in a UAC protected folder (eg Program Files)
• Insufficient permissions for Steam/steamapps folder
• The antivirus program blocks the writing of files

Step-by-Step Fix Guide

• 1
  Move Steam outside the Program Files folder (eg C:\Games\Steam)

  We'd suggest Move Steam outside the Program Files folder (eg C:\Games\Steam) first — it's the fix most often responsible for solving STEAM-DISK-WRITE-ERR outright.

• 2
  Right click on steam.exe and select Run as administrator

  Where the fault comes back, look to the later steps — they're built around uncommon runtime instability triggers.

• 3
  Add Steam as an exception in the antivirus

  "Add Steam as an exception in the antivirus" targets the Steam folder is in a UAC protected folder (eg Program Files), one of the documented causes of STEAM-DISK-WRITE-ERR.

Commands & Diagnostics

Frequently Asked Questions