How to convert mm files to feet and inch files without scaling?

[Puru]

i have done my project in mm. i want to change the format to ft and inch without scaling...

[Kyle Reese]

That does not make sense. It doesn't matter if you are going from metric to imperial or imperial to metric you will have to scale your drawing. Do it automatically via the -DWGUNITS command. Yes, the dash in front of the command is required. Pay close attention to what AutoCAD is telling you and asking you on the command line.