This window is a handy tool when you have problems and need some help from the 4TeX support team. We can only give you good help if we know which system you use and what your settings are.
The "Clipboard" button will copy the text to the clipboard and with the Paste (Ctrl-V) action you can copy it into any other program (i.e. mail program).
The "Save" button will start a save a file dialog and save the memo into an ASCII file. The "OK" button will quit the debug window.
The "Sysinfo" button will open a screen and showing you some system settings. These settings can be useful to determine what could be wrong with your system and 4TeX.