Xb file question

If you want to move your audio to a different drive, then you also need to tell Sonar where the projects and audio data is kept.

Open your preferences (P), drill down to "file > folder locations" and set the project file location. (eg: D:\Songs\)
If you have Sonar setup to create a dedicated audio folder for each project, it will store it in a folder beneath it's own location. (A song called "My First Song" would appears in "D:\Songs\My First Song\Audio\)

That works with all new projects. For old projects, you may get the dialog that it cannot find the audio files. However - once you point it to the new location - it should remember that.