When you boot into OS X (after you remove the drive), does the disc "mount" (or show up) when you pop it in?
If that doesn't work, I've read that some people had success burning a copy of their XP/Vista discs and booting from that...
Edit--
Also, you asked if it's possible to copy the contents to a hard drive and boot from that. It is possible. If the Vista disc shows up in OS X, and you have a Fire Wire hard drive kicking around, you can "copy" the contents to the FW drive using Disk Utility.
The first thing you have to do is make an "Image" of the Vista disc. From the left column in Disk Utility, click the Vista CD "session" (not the drive name like PIONEER, MATSUSHITA, ETC...) and then click "New Image" at the top. It should prompt you to save the image at this point. The Save As name should be similar to: diskXsX (X = numbers). Choose your Macs hard drive to save (say Desktop) and then choose Save.
Once the Disk Image has been created, you then want to "restore" your external FireWire drive. Click on the drive name and you should see options similar to: First Aid | Erase | Partition | Raid | Restore appear on the right side. Click Restore. The source is the "Image" you just created. From the left panel, click and drag the Firewire disk to "Destination". It has to be the Drive name (or partition) that you're draggin and not the device (Device is always First line and disk/partition follows, indented). Click Restore and wait.
Now, when you're booting, click and hold ALT/OPTION at Boot. Your Mac will search your internal and firewire drives for any bootable drives. It may take a minute or two to complete searching.
If Disk Utility hangs (because of Copyright issues with the Vista disc), you can also use Toast to make Disc Images which can be used for Restores in Disk Utility....
Good luck dhillman!
thank you! it works like a charm now. the only thing that SLIGHTLY scares me is when i boot windows vista, before it boots, a black screen shows up with some weird writings that said things like "unable to boot windows vista. error. try booting bla bla bla..." and then it repeats again and again, and then vista boots up. is that the way its supposed to be?
also, when i set my osx as the starting disk, it doesnt really boot up. it stays on a white screen with a weird huge symbol floating around... sorta looks like an a-bomb symbol/logo.. it's got a circle in the middle and 3 things around it.






















