Under the miniscule prism

Error 646

Windows Update Error Code 646

Feature ID not registered

Error 1606 on Event Viewer

Error Code 0x80070646 on Windows Update Log



When installing updates Windows Update ends up with error code 0x80070646 on XP and Error Code 646 on Vista and Windows 7 with an interpreted error message of “Feature ID not registered”.




This is an error for a User specified environment variable in the registry for %APPDATA% not properly pointing to the correct value or variable.




1.       Manually navigate into the Registry and find the registry entry for: HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerUser Shell Folders

2.       Look for the Value Name of AppData.

3.       Under AppData should be a Value Data of REG_EXPAND_SZ of %USERPROFILE%AppDataRoaming for Vista or W7.

4.       If the Value Data under AppData is %APPDATA% or any other values replace it with:


a.       FOR Vista and W7:  %USERPROFILE%AppDataRoaming

b.      FOR XP: %USERPROFILE%Application Data


5.       Install Updates. No need to reboot.




1.       Use Command Prompt to modify Registry values. Open Command Prompt in Vista and Windows 7 as Administrator (Elevated Mode).

2.       Type in Command Prompt the following syntax below (take note of each space, quotation and caret symbol):


a.        FOR Vista and W7:

REG ADD "HKCUSoftwareMicrosoftWindowsCurrentVersionExplorerUser Shell Folders" /v AppData /t REG_EXPAND_SZ /d ^%USERPROFILE^%AppDataRoaming /F


b.       FOR XP:

REG ADD "HKCUSoftwareMicrosoftWindowsCurrentVersionExplorerUser Shell Folders" /v AppData /t REG_EXPAND_SZ /d ^%USERPROFILE^%"Application Data" /F


3.       Try to install the updates. No need to reboot.




1.       Merge the embedded file below into the registry.


a.       The Registry File is in the package choose the appropriate OS: Download or Direct Link


Technorati Tags: ,,,,, Windows Live Tags: Error 0x80070646,Error 646,Error 1606,Windows Update,Error Code 646,Feature ID not registered


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s