In case you have got an intel mac, and already have your drive partitioned in Mac OS X, here is a guide to add a new windows partition without deleting any of your data or using a backup drive. These are tricks that go beyond Apple's Bootcamp utility, which wouldn't work in this situation anyway. For people into music, windows on a mac gives access to many audio tools and drivers.
This is an overview of what you need to do and not a step by step tutorial. I am only providing this information because Apple won't and many people on the internet have no clue how to do this. Do not ask me for support. Make sure you have all this stuff before you get started.
-An Intel Mac
-A Functioning Windows Install Disc
-Up to date intel versions of both iPartition and iDefrag on a boot cd (Coriolis CDmaker software lets you create a custom boot cd).
-Boot Camp drivers from apple's website, so when you do get windows running it finds all your hardware.
-Mac OS X drives that are already partitioned. This tutorial is NOT for people with a single partition (who should use regular bootcamp instructions).
-Know how to hold Option on your keyboard when restarting to select boot CDs.
Always backup your important data before messing with drive formatting...
1. Make sure Mac OS X's hard drive partition map is using GUID . iPartition (Mac OS X), on a boot cd, can convert it to GUID if it happens to be by apple. Oddly the "Apple" partition map is out of date and no longer used by apple. This happened to me, and I found iPartition is the only software that can change it.
2. In Disk Utility, select the partition you want to chop in half. Create a Fat (MS-DOS) version. It will do this nondestructively and your data will stay intact. Make sure you have enough GB for the windows install and software you might want to use later. Note: It is likely that when you get to this step that DiskUtil will fail. This may be because your disk is too fragmented with large files. If that is the case then do this:
Run iDefrag, choose the "Compact" algorithm, to free up space. This will allow DiskUtil or iPartition to make the partition without running into weird errors. You don't have to do this if the partition was created okay.
Once you have an MS Dos partition created, without bootcamp I might add, you might think you can just load your windows install CD on startup. NO! The problem lies with the Windows installer. It won't be able to see the new partition you made. It is possible to destroy your drive in the windows CD installer if it is only showing your one hard drive.
3. Boot iPartition's CD on your mac. Run iPartition from the Launcher. Select your MS-DOS partition. Go to the inspector window, then partition. Click "visible in windows." Click GO This will allow the windows CD installer to see your partition. This also prevents it from destroying all the data on your drive and breaking your Mac OSX install.
4. Run the Windows installer CD. If it sees the partition you created on the C: drive, with the appropriate amount of GB space then you may proceed. If it doesn't you have to boot back into Mac OS X or iPartition and troubleshoot. At this step you can reformat your drive to NFTS if you want, or leave it at Fat32.
5. Once the Windows installer CD finishes it will restart itself. Unfortuneately it won't do it properly. It might come up with a missing folder icon and boot you into Mac OS X. If this happens, go to your startup disk preference panel and choose the Windows install CD again. This time it should start to finish the install procedure.
6. When you have windows working, download the appropriate windows (XP/Vista) boot camp driver pack (its an exe) and put it on the desktop of your windows install. Run it. Now you should be able to do things like connect to the internet with airport express etc. TIP: If Apple's EXE doesn't run at all, you can make a driver cd in Mac OS X by clicking on the Boot Camp Utility app---->right click--->show package contents----->Contents----->Resources---->DiskImage.dmg Mount that image and make a CD copy of it with disc utility. Insert the CD when you've booted into windows.
The reason this ends up being so complicated is because Apple does not provide a disk utility that is compatible with its own hacked together drive scheme; it is only currently supported by 3rd party software (iPartition). The original Bootcamp utility works, but only in one narrow situation (a single GUID, HFS+ partition) that forces you to delete everything.
Hopefully this information helped someone. I am just posting it because I didn't find these tips anywhere on the internet. Now I can run windows audio software on my intel mac (once again).