GPG Key error in ubuntu precise 12.04

After doing some apt-get update I got this error GPG error: precise Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <> I had this since I add a new line to update my virtualbox to 5.1 in sources.list But here is the way to correct the problem.  I got […]