Have you read and followed, Installing or Upgrading VMware Fusion in Getting Started with VMware Fusion?
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If you have it installed and are having problems creating a virtual machine have you read and followed?...
Guest Operating System Installation Guide
i have read all of that and i am still confused, maybe i shoudnt be trying to do this.
ive done everything it asked to do and now i just have a black screen with writing on it that system not found
Well, in effect, you do need a disc. If you want to run Windows XP (for example) under Fusion, you have to own a copy of Windows XP. You can buy a retail copy at a computer store. Inside the cardboard box will be a CD-ROM with Windows XP on it, and a little yellow sticker containing a long string of numbers and letters. That string is your "product key."
When you go through the "New Virtual Machine" dialogue (which it sounds like you're doing) at one point you'll be invited to type in that product key.
At the very end of that dialogue, you'll see that the selected default choice is "use operating system installation disk." If you insert your Windows CD into your Mac and proceed past that screen, Fusion will boot up a virtual machine, which will install Windows into itself using that CD.
There are other ways to get a virtual machine, certainly. Let us know if this one doesn't work for you.
I would be pretty surprised if you could buy a copy of Windows at an Apple store. But you're on the right track!
Your username makes me think you are maybe in California. If so, you can go to a Fry's or a CompUSA. Any general-purpose computer store (not Mac-specific) should sell both Windows XP and Windows Vista.
My informal sense is most folks are more satisfied with their XP experience under Fusion than their Vista experience, but Your Mileage May Vary.