Windows XP Embedded, commonly abbreviated "XPe", is a componentized version of the Professional edition of Windows XP. An original equipment manufacturer is free to choose only the components needed thereby reducing operating system footprint and also reducing attack area as compared with XP Professional. Unlike Windows CE, Microsoft's operating system for portable devices and consumer electronics, XP Embedded provides the full Windows API, and support for the full range of applications and device drivers written for Microsoft Windows. The system requirements state that XPe can run on devices with at least 32 MB Compact Flash, 32 MB RAM and a P-200 microprocessor. XPe was released on November 28, 2001. As of October 2008, the newest release is Windows XP Embedded Service Pack 3.
The devices targeted for XPe have included automatic teller machines, arcade games, slot machines, cash registers, industrial robotics, thin clients, set-top boxes, network attached storage (NAS), time clocks, navigation devices, railroad locomotives, etc. Custom versions of the OS can be deployed onto anything but a full-fledged PC; even though XPe supports the same hardware that XP Professional supports (x86 architecture), licensing restrictions prevent it from being deployed on to standard PCs. However, Microsoft has made some exceptions to this rule, allowing XPe alongside a standard OEM install of Windows. Some Dell notebooks contain an embedded XP installation as part of the MediaDirect 2.0 feature, and they were also found on some Acer ones as well as the Samsung Q1.
Windows Embedded Standard 2009 succeeded XPe in 2H 2008. Windows Embedded Standard 2009 is derived from Windows XP Embedded since Microsoft at the time of its development did not have a componentized version of Windows Vista. Windows Embedded Standard 2009 includes Silverlight, .NET Framework 3.5, Internet Explorer 7, Windows Media Player 11, RDP 6.1, Network Access Protection, Microsoft Baseline Security Analyzer and support for being managed by Windows Server Update Services and System Center Configuration Manager.
Windows Embedded Standard 7 has succeeded Windows Embedded 2009 in April 2010 and is a componentized version of Windows 7.
XPe includes components known as write filters, which can be used to filter out disk writes. The volumes can be marked as read-only using these filters and all writes to it can be redirected. Applications in user mode are unaware of this write filtering. XPe ships with two write filters:
XPe adds a USB boot option to Windows. An XPe embedded device can be configured to boot from a USB drive.
An XPe device can be configured to boot from a CD-ROM. This allows the device to boot without the requirement of having a physical hard disk drive as well as provides a "fresh boot" every time the image is booted (a property inherited by the fact that the operating system is being booted from read-only media). One drawback to this technology is updating or servicing the image requires the complete process of setting up the runtime image to be completed once again from start to end.
An XPe device can be configured to boot from a properly configured network. Synonymous to CD Boot, Network Boot removes the requirement of having the physical hard drive as well as providing the "fresh boot" behavior. One bonus to Network Boot though is the ability to service the already setup image. Once the image is updated the image is simply posted to the RIS Server and once clients are rebooted they will receive the updated image.