I have an HP Pavilion notebook, running Microsoft Windows XP SP3. I have one hard disk, and two partitions. First partition hosting Windows OS, and on the second partition (created with id = AF) for Apple MacOS. MacOS works fine, using Darwin as bootloader, I can dual boot my notebook selecting "Windows XP" or "MacOS X 10.5.4".

I've installed VMWare Fusion on MacOS, and I want to be able to run Windows partition from within MacOS.

If VMWare is not seeing the windows partition as a "BootCamp" partiton.

1) Install VMWare.
2) Open terminal and type:

sudo fdisk -e /dev/rdisk0

where 0 is the number of your hd where you have the two systems.

If you get the message: fdisk: could not open MBR file /usr/standalone/i386/boot0: No such file or directory
Then move on, ignore the error message

type:

print

Here you will have a list of your partitions. Please proceed ONLY if you see the HFS+ partition flagged with the * symbol.
type:

flag X

where X is the number of the windows partition you want to use with vmware.

type:

write

type "y" and enter.

Do not exit fdisk as you will need it just in a few minutes.

3) launch vmware and you'll be pleased to see that you now have a bootcamp boot option. Follow the program instructions.

4) When you have finished to install everything and play a bit with the new toy exit VMWare shutting the machine down.

5) Go to the open terminal window and type:

flag X
where X is the number of the partition the was flagged before you changed it (the HFS+ boot partition).

type:
write
y
exit

6) Open vmware and verify that the BootCamp boot option is still there (as it was for me).

7) Try to reboot mac os (it should be all ok!)

DONE

If you are getting a b0 error, it usually means that Fusion found your 'boot camp' before you were able to set the Windows partition as active.

To get around this:

1. Make sure Fusion is not running.
2. Using Finder, go to /Library/Application Support/VMware Fusion and trash all of the folders (you should see Boot Camp and Helper)
3. continue with step 2 of the tutorial (above)

You may experience some issues with Windows Activation (WPA). I have a Windows license, and my Windows was activated. When I run it from VMWARE FUSION, Windows noticed there were some "hardware changes", and so it asked to be activated again. But I couldn't do it. It asked to buy a new one. Luckily I had a backup of wpa file and restore it, and it worked good back again. So my advise is to have always a backup of that file (normally it's located in the folder C:\windows\system32).

Extracted from insanelymac.com .... I've added some things though.