Active Desktop was a feature of Microsoft Internet Explorer 4.0's optional Windows Desktop Update that allowed users to add HTML content to the desktop, along with some other features. This function was intended to be installed on the then-current Windows 95 operating system. It was also included in Windows 98 and later Windows operating systems up through 32-bit XP, but was absent from XP Professional x64 Edition (for AMD64) and all subsequent versions of Windows. Its status on XP 64-bit edition (for Itanium) and on both 32-bit and 64-bit versions of Windows Server 2003 is not widely known. This corresponded to version Internet Explorer 4.0 to 6.x, but not Internet Explorer 7.

HTML could be added both in place of the regular wallpaper and as independent resizable desktop items. Items available on-line could be regularly updated and synchronized so users could stay updated without visiting the website in their browser.

Active Desktop worked much like desktop widget technology in that it allowed users to place customized information on their desktop.