Fix Error 646 in Microsoft Office updates in Windows 7

Windows 7 users have recently reported errors when trying to install updates for Microsoft Office applications through Windows Update or through Microsoft Update. The errors codes generated are:

Error code 1 - 0x80070646

Error code 2 - 646

Error code 3 - “Error 1606 Could not access network location %APPDATA%”

This error known by most users are the "646 error" is an MSI installer error that will only occur when the updates are installed via the Windows Update control Panel. As per Microsoft, this problem is potentially a result of an inconsistent/incorrect environmental variable (%AppData%)

Stress not, for the fix is below:

- Open Registry Editor

- Navigate to the following registry key:

HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders

- Ensure that the value for AppData is %USERPROFILE%\AppData\Roaming
To change the value, double click on Appdata, then change the string to %USERPROFILE%\AppData\Roaming

- Close Registry editor and try Windows Update again. A reboot is not necessary.

NOTE:
If the problem persists, navigate to the following keys:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders\

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders\

- Ensure that the value for AppData for both these keys is also %USERPROFILE%\AppData\Roaming

Posted in: fix Error 646, Fix Error 646 in Microsoft Office updates in Windows 7