A Live CD is a CD-Rom or a DVD-Rom with an operating system that can be executed from a bootable cd-rom or dvd-rom drive, without having to be installed in a hard drive. The system can return to its previous operating system when the computer is rebooted without the LiveCD.

Yet, there is an option with some Live CDs to install the system in the hard drive. Most LiveCDs can access internal and/or external hard drives, floppy-discs and USB Flash memories.

The biggest part of Live CDs contains a system based on the Linux kernel, but there are also Live CDs functioning with other operating systems, such as Mac OS, Mac OS X, BeOS, FreeBSD, Plan 9 or Microsoft Windows, though the legal status of Live CDs based on the Windows' code has been non other than a moot case. As for history, the first OS to do the job, support Live CD operations in other words, came out in 1991, and was identified as Mac OS 7.

The Microsoft has released a tool of great use to system administrators and all personal computer professionals, the so called Windows Preinstallation Environment (WinPE). It is a modified, short version of the operating system based on the Windows XP kernel.

In fact, WinPE lets you boot up your personal computer in a Graphical User Interface (GUI) and at the same time, control the configuration of all your system. You can then format a partition, have access to files on your hard disk or to other computers in your local area network, or use some external devices (if you have the correct drivers).

WinPE comes in a bootable CD-Rom, so the user can boot up the system in emergency conditions or take advantage of its graphical environment to create or, for instance, handle a partition. It is also possible to get files from other computers using TCP/IP and run some diagnostic tools for the hardware already installed.

Unfortunately, WinPE is available only to the OEM producers. The Microsoft, however, must add WinPE in the next version of Windows “Longhorn”. This, in fact, should replace the classic text interface of the Windows setup.

For the time being, the fact that the final user is incapable of being in possession of the MS WinPE has led Bart Lagerweij to create a program called Bart’s PE Builder. This software enables you to create a Windows LiveCD with a graphical interface quite similar to the WinPE and boot up your system.

Bart's PE Builder can be used by anyone who wishes to build a "BartPE" (Bart Preinstalled Environment) bootable Windows CD-Rom or DVD from the original Windows XP or Windows Server 2003 installation-setup CD. It supports a complete Win32 environment with network support, a graphical user interface (800x600) and FAT/NTFS/CDFS file system.

PE Builder is not a Microsoft product and does not create Microsoft Windows Preinstallation Environment (WinPE). Using PE Builder does not grant you a license to Microsoft WinPE or to use the Windows XP or Server 2003 binaries in a manner other than stated in the End-User License Agreement included in your version of Microsoft Windows XP or Windows Server 2003. Apart from the fact that the Microsoft has not reviewed or tested PE Builder and does not endorse its use, it does not provide support for the PE Builder or for the preinstallation environment created by the PE Builder. (adopted from the BartPE official website)

The PE Builder program can run on Windows 2000/XP/2003/BartPE but does not run on Windows NT4/ME/9x.