If you are scanning a CD-ROM, then Hi Lab will initially
suggest saving the index file on the CD-ROM.
As it is not possible to write to (most) CD-ROMs,
you should save the index file to your local disk.
To make the index access the CD-ROM, you should alter the
first Base URL so it points to your CD-ROM drive,
eg in Windows if your CD-ROM is drive D:, then set the Base URL to
(note the correct use of forward slash and bar characters).