• Virtual PC is a Microsoft product that installs a software PC on your hardware PC. The virtual machine that's created by Virtual PC can run applications, play games, browse the Internet and do almost everything your hardware PC does. This virtual machine is a self contained environment that creates a barrier between itself and your hardware PC. With a properly configured Virtual PC you can surf the Web safely and test software without affecting your computer.
  
  

Run Virtual PC from a Separate Hard Drive

• Since hard drives cause most of the virtual machine bottlenecks, it's important to install Virtual PC on a different drive than the one its operating system (OS) is using. The OS constantly accesses the registry, drivers, services, system files and swap files, so it's a bad idea to make it share a drive with your virtual machine. Since Virtual PC creates an entire computer in software, it also reads a lot of data from your hard drive and writes a lot of data to it. If you install your virtual machine on a separate hard drive, that drive won't be tied up by the operating system when Virtual PC needs it.
  
  

Apply the Latest Service Packs

• It's important to keep the operating system and virtual machine up to date. Just as Microsoft releases service packs that improve the security and performance of Windows, they also release Virtual PC add-ons (virtual machine additions) that fix bugs to make Virtual PC more efficient. To install the latest virtual machine additions, run Virtual PC and select "Install" or "Update" from the "Action" menu. Click "Continue" when the dialogue appears and follow the prompts.
  
  

Defragment Your Hard Drives

• With all of its input/output processes, Virtual PC puts many demands on a hard drive. Just like the OS, if it can't access files quickly it will start up and run slower. That's why it's just as important to defrag the hard drive of your virtual machine as it is to defrag the drive that holds the OS. If disk space is a problem, you can compress your virtual machine's drive without affecting Virtual PC's performance.
  
  

Disable Unnecessary Devices, Programs and Services

• Every resource that ties up the OS can reduce the performance of your virtual machine. You should disable these resource hogs whenever possible. If the OS and applications aren't using your COM 1 and 2 ports, your LPT port 1, or your CD drives and USB adapters, you should disable them to release IRQ (interrupt request) resources and eliminate sharing conflicts (you can do this through the device manager.) You should also turn off screen savers and other unneeded programs and services.