Removing X3 before installing X3 Producer

While removing X3 will only free up about 200MB of space, there is no reason to have X3 and X3 Producer installed on the same machine. After running the uninstall for X3, you may want to also clean up the registry by removing the keys:
HKEY_CURRENT_USER\Software\Cakewalk Music Software\SONAR\X3
HKEY_LOCAL_MACHINE\Software\Cakewalk Music Software\SONAR\X3
and the user directory c:\Users\yourUserName\AppData\Roaming\Cakewalk\SONAR X3
NOTE: if you have added any customizations to this directory such as changes to the ini files, master.ins, drum maps etc. you may want to delete this directory after integrating the custom bits into the new X3 Producer user directory.