Unfortunately the registry key is recreated by Acrobat updates. To prevent the Acrobat Chrome extension installations for new users, prepare the file C:\Users\Default\AppData\Local\Google\Chrome\User Data\Default\Preferences with the following content: {"extensions":{"external_uninstalls":["efaidnbmnnnibpcajpcglclefindmkaj"]}} This indicates that the extension was already previously uninstalled by the user. ... View more

I have deleted the registry key that installs the Acrobat extension for all users. Now no more Error is showing on the first start of Chrome. This is not exactly the issue with a new tab opening, but extremely annoying for new users and inappropriate for a business environment. I have no experience yet if updates will reenable it or not.   On 64-bit Windows delete the registry key HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Google\Chrome\Extensions\efaidnbmnnnibpcajpcglclefindmkaj On 32-bit Windows delete the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Google\Chrome\Extensions\efaidnbmnnnibpcajpcglclefindmkaj   ... View more