Virtual PC for Windows 5.0 boosts performance over the last version. It's the best emulator around for running multiple Windows or Linux OSs on one PC.
Specs: 1 user, Complete package, Microsoft Windows 95, Microsoft Windows 3.1, Microsoft Windows 2000 Server, Microsoft Windows NT Server 4.0, Microsoft Windows XP Home Edition, Microsoft Windows XP Professional, Microsoft Windows 2000 Professional, Microsoft Windows 98 Second Edition, Microsoft Windows Millennium Edition, Microsoft Windows 2000 Advanced Server, Microsoft Windows NT Workstation 4.0 SP6 or later, Microsoft Windows NT Server 4.0 Enterprise Edition, Intel Pentium 400 MHz, 5, CD-ROM, Intel Pentium, 400 MHz, Windows