Discs with logical defects in the file system can produce unpredictable failures - they work fine on some computers and not at all on others. CD Structure checks the contents of a CD or DVD against standards to ensure successful duplication. The ISO-9660 standard with XA, Joliet and Rock Ridge extensions must be complied for a disc to be able to be used in all environments. Much of the mastering software that is available today does not comply with these standards and when this is used there can be difficulties with duplicated discs. CD Structure does not require a dedicated computer or special hardware to function. It can be used with equipment you already have.