Has anyone installed Windows on an intel mac? If so and I want to get rid of it in the future is there any way that I can make that partition part of the OSX partition again?
You just use Bootcamp to delete the partition. It gives you the option to do so if a Bootcamp partition exists.
One thing to note, if you’ve had an Intel Mac for a while, the drive may be fragmented. OS X defrags small files on the fly but not larger ones and this fragmentation may cause Bootcamp to give you an error that it can’t partition the drive because it can’t move some files. What you have to do then is clone it to an external drive (good idea anyway), format/erase it but no need to zero it, then clone it back and use Bootcamp again. If it’s a new system, it will probably work first time.
It also need an XP SP2 CD, you can’t use say an SP1 CD and then update it.
When you split the partition, try not to divide it equally because it’s hard to distinguish between the drives in the Windows boot screen.
As for format, weigh up what you will use it for. I like FAT32 because it allows me to easily copy stuff from OS X. OS X currently has no write support for NTFS but some recent developments suggest it could come in the form of MacFuse. FAT32 has a 4GB file size limit and you can only get a 32GB partition. This should only be a limitation if you do work with DVDs but I do all that stuff on the Mac side.
Can you get a smaller partition? I was thinking about 20gb
Yes, you can go all the way down to 5GB. I settled on 10GB because I only need enough space for one or two games at a time. The biggest games I’ve installed were about 4.5GB each.
I think you should be able to use an external firewire drive. That way you don’t need to repartition your main drive.
Windows doesn’t support booting from external drives by default. You have to hack it around to get it to work. I couldn’t even install the XP CD from an external firewire DVD drive.
Here’s the process you need to go through to get it to work:
http://www.ngine.de/index.jsp?pageid=4176
Windows embedded is designed to do this but I don’t know if the Intel Macs support it. I don’t understand why they need different OS versions for everything. Embedded, pro, home, media center, 64-bit. OS X does all that in one version.
I know it doesn’t for PCs, but I think on a mac it will be different. Macbook’s aren’t exactly the same as PCs… one difference between the intel macs and the boot loader is the BIOS. Doesn’t Boot Camp work by making a BIOS emulation module on top of EFI? I haven’t tested it, but I think it’s worth a shot.
No, I tried it already with both USB and firewire and the XP installer saw the drive but it won’t let you install onto it.
Running Windows on a Mac via Bootcamp uses no emulation. There was a firmware update ages ago which installed bios support and all the new Macs have that update already. All that Bootcamp does is partition your drive and burn a drivers CD, nothing more. You can actually install XP without Bootcamp if you wanted to, it would just overwrite your OS X partition. There is no overhead running Windows directly on a Mac, it runs just as badly as it does on a PC. 
I tried to do it and I got an error message. It said I should turn of caching or shaddowing. What does this mean and how should I do that?
Is this the SESSION3_INITIALIZATION_FAILED error that appears after you start installing XP? It’s to do with the CD you are using apparently. If you try another CD it might work. What some people have had success with bizarrely is copying the original installer and just using a direct copy:
http://www.techlearning.com/story/showArticle.php?articleID=192700194
You shouldn’t need to remove the partition as someone suggested on the site. It’s a problem between the disc and the drive. I managed to install from both a proper CD and a copy without this problem on different machines so I’m not sure what causes it.