 To be backwards compatible with the 8.3 limitations of the old File Allocation Table filenames, the names 'Program Files', 'Program Files (x86)' and 'Common Program Files' are shortened by the system to codice_11 and codice_12, where "N" is a digit, a sequence number that on a clean install will be 1 (or 1 and 2 when both 'Program Files' and 'Program Files (x86)' are present).If Windows is installed on an NTFS volume, by default, the 'Program Files' folder can only be modified by members of the 'Administrators' user groups.This can be an issue for programs created for Windows 9x.