The mm.cfg file is a golden mine for any Flash Platform developer. Basically it allows you to log a lot of useful information from your running apps.

Recently I had problems making it work on my new Windows XP machine at work. According to the official adobe docs all I had to do was put this file in C:\Documents and Settings\Username and put whatever configurations I wanted there. But no matter what I put in, it never seemed to generate the log file.

After a little more research I discovered that the correct path for Windows XP seems to be %HOMEDRIVE%%HOMEPATH% which by default is the Documents and Settings path. But that is only your sys admin decides something different. For me the path was Z:\ , a mapped shared folder on the network. Once I copied the mm.cfg file there everything started working and the if flashlog.txt file was created at the proper location : C:\Documents and Settings\Username\Application Data\Macromedia\Flash Player\Logs . I also found this technote from Adobe which also states that the location might differ on Windows XP.

How to find your correct path ?!
If you want to find what your homepath is just open up a windows commander console and type echo %HOMEDRIVE%%HOMEPATH% .