A. To clear the waiting files, select the folders/files from the "Files to add to the CD" area and press Delete. However, if you want to clear all the files, right-click the CD-Recordable (CD-R) drive and select "Clear staging area" from the context menu.

You can also manually delete the files, which are stored in the %USERPROFILE%\Local Settings\Application Data\Microsoft\CD Burning folder. You can change this location by modifying the registry value HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\ExplorerShell Folders\CD Burning.

От себя добавлю:
не забудьте сделать log off