Hi,
If any program besides Office is causing the problem, please try the following procedure initially:
Open the command prompt (admin) and run the commands: sfc /scannow and dism /online /cleanup-image /restorehealth. Wait for the process to finish and restart the computer.
Then perform a clean boot and uninstall any applications you don't use.
What happens when it freezes and the screen goes black or a BSOD occurs?
Thanks