it happened to me to notice that after uninstalling Orbit downloader, google Chrome still tried to use Orbit to download files, obviously without success.
So there are 2 things you can do now:
1. disable the plugin
2. delete the plugin
The instructions are for Orbit, but the same is valid for every plugin.
== DISABLE PLUGINS ==
in the address bar write:
search for Orbit downloader and click on "Disable"
== DELETE PLUGINS ==
FIRST close Chrome!
from the start menu execute:
to go in the local application data folder
(something like: C:\Users\username\AppData\Local)
then go to the subfolder
search for the plugin's .dll file (in this case, for Orbit it's "nporbit.dll") and delete it.
Open Chrome, the plugin disappeared