Where in the sequence can you access INSTALLDIR and SUPPORTDIR files?

[jmorgret]

I am trying to determine exactly when the installed files become available in the install sequence.
To clarify:
I have a component containing two files. I need to run a CA against these two files once they are in the INSTALLDIR. Everywhere I put this CA, the files are not there yet. If I put it at the very end then the script file I am using in the CA (which is stored in the SUPPORTDIR) is gone by then.

Is my only option to copy the script file to something other than SUPPORTDIR so that it doesn't get removed? Or is there a place in the sequence where both the files in INSTALLDIR and the files in SUPPORTDIR are accessible.

Thanks,

Jennifer

[luke_s]

The files are only accessible after InstallFinalize because this is where all of the transaction scripts are executed.