not sure what you mean here. can you elaborate?
I mean which adb.exe file is used when compile *.as (action script) files within a flash builder environment ?
could you provide a path to adb.exe ?
I'm not exactly sure, but I'm sure you could take a look in the AIR SDK and find out.
On windows, it should be located at:
C:\Program Files\Adobe\Adobe Flash Builder 4.7 (64 Bit)\eclipse\plugins\com.adobe.flash.compiler_184.108.40.2069722\AIRSDK