The toribash directory is located in:
My Computer<Local Disk<Games<Toribash
To view other people's replays, click on the replay and select "Browse" and highlight the TB engine, named "tb.exe". After you do that, you can choose to "always select this program for this type of file" so that whenever you click on a .tbm replay, it will automatically open the TB client without all the unnecessary hassle.
The TB engine is located in:
My Computer<Local Disk<Games<Toribash<tb.exe