Are you talking about the boot screen that initially pops up? This is the PC's bios showing you that it is working.

First let me ask what you have installed thus so far? what did you change? How closely did you follow the instructions on the linked site I pointed to?

To get your system to recognize your install you need your Hard Drive's partition table to have a partition marked as active.

1. Boot into your Mac installation DVD
2. Select Utilities -> Terminal:

a. diskutil list
b. fdisk -e /dev/rdiskX where X is the drive # you installed to seen in step A
c. update
d. f Y where Y is the partition you installed to seen in step A
e. w
f. answer y
g. q
h. reboot

Your system should boot to the OS you pointed it to.

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