question: public boolean isFixedDisk ( String letter ) { if ( letter . length ( ) != 1 ) throw new IllegalArgumentException ( "Supply 1 letter, not: " + letter ) ; char drive = Character . toUpperCase ( letter . charAt ( 0 ) ) ; if ( drive < 'A' || drive > 'Z' ) throw new IllegalArgumentException ( "A drive is indicated by a letter, so A-Z inclusive. Not " + drive ) ; return getDriveType ( drive + ":\\" ) == 3L ; }
target:  Feed it a drive letter (such as 'A') to see if it is a fixed disk.