Error 0x80070660: The Temp folder is full or inaccessible

When you install software that uses the Microsoft Installer (.msi), the error code 0x80070660 may occur. The following is the entire error message:

0x80070660 - The Temp folder is on a drive that is full or is inaccessible. Free up space on the drive or verify that you have write permission on the Temp folder.

Cause

The above error can occur due to one of the following reasons:

• The “C:\Windows\Installer” folder is missing. This folder is the Windows Installer Cache folder, which stores essential files for apps installed using Windows Installer. (or)
• The c:\windows\temp or the user %temp% folder permissions are incorrect.

Resolution

To resolve the error 0x80070660 (“ERROR_INSTALL_TEMP_UNWRITABLE”), follow these steps:

Step 1: Create the missing “Installer” folder.

The Windows Installer Cache folder “c:\windows\installer” is an important folder that should not be deleted. If it’s deleted, problems arise when uninstalling, repairing, or updating a program.

To recreate the missing folder, follow the steps below:

Open an admin Command Prompt window and run the following command:

md C:\Windows\Installer

Re-run the installer package now.

If that doesn’t fix the issue, fix your temp folder permissions as mentioned in Step 2 below.

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Step 2: Fix the Temp folder permissions

Follow these steps to fix the permissions for the system Temp folder and the user’s Temp folder.

Open an admin Command Prompt window.

Type the following commands exactly as given below, and press Enter after each command:

takeown /f c:\windows\temp /a
icacls c:\windows\temp /reset
icacls c:\windows\temp /inheritance:r
icacls c:\windows\temp /grant Administrators:(OI)(CI)(F)
icacls c:\windows\temp /grant SYSTEM:(OI)(CI)(F)
icacls c:\windows\temp /grant "%username%":(OI)(CI)(F)

Tben, run the following commands to fix the user’s Temp folder permissions:

icacls %temp% /inheritance:r
icacls %temp% /grant %username%:(OI)(CI)F /T /C
icacls %temp% /grant Administrators:(OI)(CI)F /T /C
icacls %temp% /grant System:(OI)(CI)F /T /C
md %temp%\Low
icacls %temp%\Low /setintegritylevel (OI)(CI)low

(For more information on fixing the %temp% folder permissions, check out this article.)

That should resolve the error 0x80070660 when running a .msi setup package.