In ColdFusion 5 (and older versions), you could use the CFREGISTRY tag to lookup the location of the ColdFusion install. This was a handy feature - especially if you wrote ColdFusion code to deal with files and directories under the ColdFusion root (not the web root) and didn't want to hard code the values.

In older versions of ColdFusion, the default install location was c:\cfusion. In ColdFusion MX, it's c:\cfusionmx.

Because CF MX no longer uses the registry to store configuration information, you obviously can't use CFREGISTRY to lookup the install location. There is, however, a new server variable that you can use instead:

SERVER.COLDFUSION.ROOTDIR

This variable gives you the full path to the ColdFusion root directory.