While Setup extracts the Precopy CAB files, it performs a throughput calculation to determine the time remaining to complete setup. The timer is not a good indicator for the actual time remaining if Setup stops responding. Also, if certain files are not needed for a particular type of installation, they are not copied. A cabinet is a normal file that contains pieces of one or more files, usually compressed. The Windows 98 files are read, then written as one continuous byte-stream, which is then divided into folders as appropriate.
Folders can fill one or more cabinets.
The Windows 98 cabinet structure has changed slightly from that introduced in Windows 95. The enumeration of Plug and Play hardware is moved to the first boot portion of Setup. Enumeration is performed before detection to reduce hardware detection problems and errors . When you start Setup, it checks if any anti-virus programs are running. If there are, Setup displays a dialog box informing you to disable the software.