Hi everyone! First, Sorry! if this question is already answered!

(I have xp on my system with four partitions)

I installed mac osx86 on my fourth and last partition from a dvd called "brazilmac 10.5.5" and patched as they said (9a581PostPatch.sh stuff with USB Drive)

These are my PC specs...
Intel Dual Core CPU 3.4 GHz (945 Presler supports SSE2 and SSE3)
Gigabyte GA945GZM-S2 v3.0
2GB RAM
...................

After i did everything it does not show anything in bootloader to boot into osx (it directly boot into XP)

I am completely new to this.... please tell me what to do!!!!!!!!!
thanks in advance

check your BIOS options for your HDD boot preference

you should also have a boot selection option key.. (usually F12)
that you can hit at the post screen to bring up a choice of OS.

if you do nothing it will default to the last successfully booted OS

Have you made your OSX partition active? If not then first make it active from Disk Management in Windows XP and check.