If the web tab is missing in the Desktop Items dialog box after clicking the customize desktop button. Then some policies like Active desktop might have been disabled. You can change this feature or setting in group policy editor. Well, here is a registry which will re-enable the active desktop properties.
Under these conditions you can just open Registry editor and navigate to the following registry values.
To open registry editor go to Start > Run > regedit.
Go to >
HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ ActiveDesktop and delete the Nocomponents key.
HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ Explorer
Delete the NoActiveDesktopChanges registry value in there.
HKEY_LOCAL_MACHINE \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ ActiveDesktop and delete the NoComponents key.
HKEY_LOCAL_MACHINE \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ Explorer
Delete the NoActiveDesktop registry key.
Do not forget to always back up the registry before working on it because registry contains sensitive data.
It might be necessary to restart your computer to observe changes.
Under these conditions you can just open Registry editor and navigate to the following registry values.
To open registry editor go to Start > Run > regedit.
Go to >
HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ ActiveDesktop and delete the Nocomponents key.
HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ Explorer
Delete the NoActiveDesktopChanges registry value in there.
HKEY_LOCAL_MACHINE \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ ActiveDesktop and delete the NoComponents key.
HKEY_LOCAL_MACHINE \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ Explorer
Delete the NoActiveDesktop registry key.
Do not forget to always back up the registry before working on it because registry contains sensitive data.
It might be necessary to restart your computer to observe changes.