MS "free" accounting software?
I think you're talking about Money, and that would make as much sense as having Access as a corporate DBMS.
Here in Mexico, two local software companies have competing products for most accounting / inventory stuff solutions, and those are the ones that basically eat up the SMB market, *not* Microsoft. So at least in the Mexican market, Microsoft isn't even there; SMB's go the SAE or ContPAQ way, or jump up to high-end stuff like SAP R/3 or other full ERP solutions.