Error 0xe001f90f happens in AVG while updating and uninstalling the antivirus software. And to fix this, you need to:

• Run the AVG remover utility tool and select the AVG products you would like to remove.
• If you want to uninstall the software, click the ‘uninstall’ button to remove it fully and install it again after you restart the computer.

If the problem still remains, consult with the experts at Avg antivirus customer service to aid you in solving the problem.