Failed in GetCertificate(…): 0x80040281
If you get this error whilst installing the SCCM agent then that could mean that you’re executing an older version of the ccmsetup.exe file. This can happen if you’re using the SCCM right-click tool or if the computer was previously installed with an older version of SCCM agent e.g. SP1 and you’re still using that to trigger an install of the agent. Be sure to get the latest ccmsetup.exe file from the Program Files folder after you’ve upgraded your site to SP2 or any higher.