I'd make sure those virus/malware scans are done properly.
First, delete AVG. It's useless.
Download and install Malwarebytes, update it.
Reboot, smash f8 until you get a list of options and run malwarebytes and let it scan, delete anything it finds.
Once done run Avast and do a full scan, delete anything that finds as well, reboot and try opening office. Could always just do a reinstall if there's still errors, could be a corrupt file if whatever the virus was has messed around with any of the office dll's or executables.