BSoD after changing to AHCI

Hello everyone,
I've been searching on the web for this problem for hours now, I've installed Microsoft fix, Followed other guides which said :
Change iaStorV Start to 0 (earlier it was 3)
Change HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msahci]
"Start" to 0.

Steps i'm doing, I go into Bios then i change the Sata to AHCI (Its currently Raid). I save and exit. Right before the Log-in Screen I crashes.

I do not want to re-install my OS because it will take a lot of time to re-install all of the programs and drivers.

Edit 1: I have a SSD drive, I tried using the Diagnostic tool but its telling me Sorry No dump found .

Hiyya and welcome pokkidief suppose you didn't do any back ups to an external by any chance? If not well... it might be the long haul again mate but take a look at this

AHCI : Enable in Windows 7 / Vista

it might not solves the problem but good for future refs eh?

Unfortunately it looks that way mate - sorry. You really need to set the ACHI in the BIOS before you install to get it really right.

You have the OS disk (I am assuming you built this machine?) or not?

If you built the machine and have the disk I might suggest you wipe the disk first - the Partition Wizard is good for that or clean all in DISKPART (long winded)
Partition Manager Server, server partition manager and partition magic server for Windows Server 2000/2003/2008. Server Partition software for Windows Server and None-Server partitions < handy tool for other stuff too and the wipe depending on your system specs and speed will do that in say around half hour.

Before you install use this tutorial too if you haven't already

SSD Alignment I printed it off for reference as unless you have a second machine to read from there is no way of following it ( I know I am stating th obvious but..) plus I always use it for all new drives (1st page) for prepping SSD's and HDD's

Let us know how you go