I was finally able to upgrade my system. I installed Win 7 in IDE mode. After changing 'Start' to 0 (from 3) in :
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\pciide
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msahci
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\iaStorV
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\iaStor
I can boot Win 7 in IDE or AHCI mode by just changing the BIOS setting. ( After booting in AHCI mode I even installed the latest Intel AHCI driver ).
Can something like that be done for Win 8/8.1 ? There is a lot of info on how to switch from IDE to AHCI mode but after doing that Win 8/8.1 will not boot in IDE mode.
btw : I'm not using a SSD. My h/w : Haswell + Z87.