I have ACAD 06, but just upgraded to 09 mechanical, and I am wondering
how to make 09 my default program instead of 06. Do I have to uninstall
06?

[QUOTE=DeanJaan]I have ACAD 06, but just upgraded to 09 mechanical, and I am wondering
how to make 09 my default program instead of 06. Do I have to uninstall
06?
[/QUOTE]No because 09 it will be default just install it.Many programs of Autodesk you are able to install in a PC.

Hi DeanJaanDo you mean that you have ACAD 06 and ACAD Mech 09 both installed and if you select a .DWG file it opens up ACAD 06, but you'd rather that it started Mech 09?If so, depending on the OS (this will work for XP) you need to assign the file types a different application..Start -- > Control Panel --> Folder Options --> File Types tab --> DWG or whatever file type / extension you want to change and then press the Change... button.  This will open the Open With dialog box and you should be able to select Mech 09 in there.HTH

Do you mean you want to open drawing using 09 by double clicking the
file? Firstly, right click a dwg and choose to Open with-> Choose
program, and from the list of programs select 09, also tick "Always use
selected program to open this kind of file."However once you open
the 06, the default open choice will change to 06 and will not default
open with 09. The next time you have to rechoose the "open with"
program.