AHCI Boot Problem!

Hil all! :)
Im back after some time and yet again another problem I've faced and found the solution, wanted to share it with everyone.

Okay, lets jump to the topic. 

I have a windows 7 installation 64 bit ultimate. to gain high access speeds I had my SATA HDD AHCI enabled, and the pc was working fine. (how to do it - it explains the hassle free way of doing it).

and what happned is i was using my pc, copying some files to my pendrive and boom! power cut. The pc went off since i got no ups :( so hdd stucked while doin an I/O operation. but after power cma eback, it worked fine, windows loaded, so i didnt bother(I could've fixed it if i do a chkdsk or defrag at that point - I think! )

After I shutdown the pc next day boot up - the windows doesnt load! the painful......

 

.. came up!

things I did -

1. windows 7 cd -> startup repair :(
2.  command promt at win7 cd -> bootrec /fixmbr, bootrec /fixboot( got it from here, couldnt do the last one though :( that also might have saved my a** lol)
3.  command promt at win7 cd -> chkdsk /f c: 

So, decided to re-install windows.
so put the cd -> booted -> copied files ->restart and then..

 ..hangs here. the colored squares even wont load. it just hangs and if u press power button, it shuts off.)

I did,
  

1.  format c: -> install :(
2. deleted  c:-> created again -> install :(
3. deleted c:->created a small partition just for windows -> installed :(

nothing worked.

I was about to plug out the HDD and take it to the seller for warranty claim, after hours of data backing using Kaspersky Rescue Disk(Which boots up using a linux distro, you can copy paste anything to a USB except windows user folders. Use win CD and go to command prompt and use xcopy to copy them, to a different folder beforehand) I did a small thing.

In bios, I changed raid mode back to IDE instead of AHCI.

Restarted. took little more time to boot, and Hola! windows setup loaded!!!


conclusion- Win 7 cannot be installed while AHCI mode is on.