You say 'Microsoft Word/Excel would freeze'.
If this is the case then the issue is not Word, and removing Normal.dot will not help.
BTW, if you didn't find Normal.dot, your search is probably not set to look in hidden folders or system folders.
Look in the 'More Advanced Options' in the search window.
If disabling the MalwareBytes scan doesn't work, try uninstalling it and restarting your PC.
Another route to seeing what is happening is to go to Windows Task Manager (Ctrl+Shift+Esc) and look in the processes tab when Word or Excel has frozen and see if any program is using lots of CPU time.