wattage said:
Be sure you read close. Virtual PC requires you purchase an individual copy of Windows, a system disc that came with another PC will not work. So there's another few hundred bucks.
Virtual PC can be purchased as just the VPC emulator for which you need to seperately obtain a valid Windows license and install media from which to install Windows. (Assuming you want to run Windows.)
Alternatively, Virtual PC can also be purchased in versions that include a license for Windows. In this case, installing Virtual PC with Windows onto your Mac is a one step process since Virtual PC ships with a Windows disk image. There are Virtual PC editions that ship with most current versions of Windows.
Personally I've always used the bare-bones version of Virtual PC since I've also used it to run Linux, NetBSD and NextStep at various times. I found the Virtual PC only version works best for me.
With VPC, you have two choices for where you install Windows. You can either allocate a hard drive on your system to Windows. Usually this will be an external drive and the install of Windows on that drive is a complete installation of Windows. That is, ignoring driver issues, you could plug this external drive into a Intel PC and boot off the external drive.
The second approach involves using VPC to create a file on your Mac hard disk. This file is used as a disk image onto which VPC will isntall Windows. The disk images used by VPC can either be allocated a fixed image size or they can be set up as a variable size image. For a variable size image during the Windows install you set the maximum image size and this is the size of the disk that Windows sees. However the file size of the image in the Mac files system is only the size of the used space in the Windows drive.
For example, you can set up an image with a maximum size of 20GB. If you then install Windows onto the image along with a few applications you might end up with 2GB of used disk space in Windows. If you are using a fixed size image file then in the Mac file system the image file will be 20GB in size. But if you use a variable size image file then the image file in the Mac file system will only be about 2GB in size since unallocated space on the Windows file system does not need to be stored.
Virtual PC tip: VPC asks you at the end of each VPC session whether you want to commit the changes to the Windows disk image. The only time say yess to this is when I first install Windows, apply the service packs and install the applications I need. During any other session I always ensure that my data files are saved in the Mac filesystem and do not allow file system changes to be applied to the Windows image. The result is that whenever I start VPC I always have a fresh Windows install and this helps avoid some of the stability issues that arise with Windows.