The short answer is: You Can't.
It seems to be a popular question as to whether you can install/run Mac OS X under virtualization within Windows. However, most of the questions really answer the reason as to why you can't.
If you have any tips that contradict this post, and actually allow you to install/run Mac OSX within Windows Virtual PC, please post them. Thanks.
See the following URLs:
VMWare Mac OS X Guest Package
VMWare How To (OSx86 Project)
Be mindful of the license.
Can you run OS X on Windows? Yes, apparently you can with PearPC. Is it legal? Well, that is another question on its own.
While it is possible (which is what you asked), there are certain limitations:
While the CPU emulation may be slow (1/500th or 1/15th), the speed of emulated hardware is hardly impacted by the emulation; the emulated hard-drive and CDROM e.g. are very fast, especially with OS that support bus-mastering (Linux, Darwin, Mac OS X do). A lot of unimplementated features are fatal (i.e. will abort PearPC). Timings are very still a little bit inaccurate. Don't rely on benchmarks made in the client. PearPC lacks a save/restore machine-state feature. No LBA48 (but LBA). Currently no support for hard disks greater than 128 GiB. Disks > 4GiB are not tested very well.
Here's a post that contains a couple reasons why you can't. The reasons are also listed below:
This is not possible for three reasons:
1) Apple does not allow this in their OS licensing
2) Mac OS X specifically checks to ensure that it is installing on Apple hardware
3) Mac OS X requires that the computer has an APIC - which we do not emulate
