I guess simplest way to fix this is to let AC9 and 10 be and re-install 11. Then XP should open your files in AC11 by default. The better way is to create desktop shortcuts for all programs, and always open the program by double-clicking those. Then you have full control.
AC4.1-AC24SWE-25INT; OSX11.5; MP5,1+MBP16,1