My first post on the forum, Just want to say thank you OP for this excellent tutorial and I am now a happy Hachintosher (very likely will get a legit copy of Mac soon as I am rather impressed by how smooth the OS is).
Now just so it might help other owner of HP m9250f, I used iAtkos 7 DVD (10.5.7, bt download). Basically what I did:
1. Flash the 5.17 Mod flash. (didn't try without it but I guess it's a must? At least it doesn't do any harm).
2. Set BIOS as OP instructed.
3. Installed on a 2nd 500GB HDD (it wasn't used anyway, so my vista is still intact). This way I can dual boot but each time have to change in the BIOS either RAID or ACHI.
4. The customization options when installing the iAtkos 7 is slightly different from what OP described but I just followed the basic judgement and it worked the first try! Now all I can remember is (not complete, follow OP's instruction for most part)
-Chameleon v1 as the bootload
-Intel speedstep driver and throttling control.
5. After installation it booted very speedy into the system.
6. Using Kext Helper b7, I installed the Audio driver and sleep fix provided in thread 1.
7. I know that my wireless chipset is RT2571WF, not sure whether that's the same as OP but I found on the official website the provided driver is different. So I downloaded that driver instead. After install and restart, the USB wireless utility didn't found anything so i hot unplug and plugged the wireless chip and it was detected and has been working since then.
8. Somehow, at the beginning (like ten times restarting the router and the computer) the ethernet kept getting a 169.xx like IP and wont go online. Eventually, lucky me that my router can be flashed into a DD-RWT firmware so I did that under vista and the ethernet had worked since then.
9. I have also the HP media vault 1 generation. I tried to follow HP website instruction but under Network of the Finder it just wouldn't show anything, even though I can log onto the router (192.168.1.1) and the HP mediavault (192xx) by firefox.
10. Eventully under Finder\Go\Connect to server, instead of Browse, I used smb://192.168.1.149 (my HP MV's IP) and it found the HP right away!! Weird why it can't find it by the Network itself (well lots of time Xp or Vista does this as well, can't detect the workgroup neighbour but using the IP they can be found).
11. My Canon printer comes with Mac driver so installation is smooth.
12. Some other small problem I will report in next post.
To conclude, very functional and stable Mac OS X is now running on my HP m9250f PC. Thanks OP again and hopefully you can help me with some other small questions in the next post. Cheers!