Microsoft has released Virtual PC 2004 Service Pack 1 as a free virtualization software to public for free download. Virtual PC 2004 is a virtual desktop computer BIOS and environment for Windows that allows users to run multiple instances of operating systems on a single computer by creating an entirely software-oriented computer with a disk-based image, running on a version of AMI BIOS that simulates as a physical computer to whatever guest operating system, and shares physical devices such as optical drive and network interface as a virtual machine.

Microsoft Virtual PC 2004 (VPC) mainly supports Windows operating system as guest operating system on virtual machines, namely MSDOS, Windows 95, Windows 98, Windows ME, Windows NT, Windows 2000, Windows XP, OS/2, Windows NT Server, Windows 2000 Server, Windows 2003 Server, and Other, which may be Linux. The virtual machine allows users to test a new development environment, experiment with applications on other operating system or simply try out a new configuration without changing the underlying OS.

Microsoft’s Virtual PC 2004 SP1 software requires Windows 2000 Professional SP4, Windows XP Professional or later, and Windows XP Tablet PC Edition or later. The download size of VPC 2004 SP1 is 18.2 MB.

The new version of the virtualization software, Virtual PC 2007 for Windows Vista will also be available for free download. Virtual PC 2007 will enable support for Windows Vista and performance enhancements.

Download Virtual PC 2004.

Update: Virtual PC 2007