The way to disable a Time Matters addin is to do so through the Time Matters application itself.
Launch Time Matters by right clicking 'Run as Administrator' - you'll need your PC's Admin password for this. Then click:
File>Setup>General>Workstation Level>External Program Setup
then uncheck the Word-related checkboxes to remove the Time Matters Word addins.
Deleting the tm8word.dot file might work, but Time Matters might have a hissy-fit about that...
It might also be worthwhile checking for an updated Time Matters addin (not just the tm8word.dot file) and/or taking the issue up with Time Matters directly, through their product support page:
http://www.lexisnexis.com/business-o...t/time-matters