IDE to AHCI in Windows without re-install
I came across this issue the other day, having run a new install on a caddy drive of win 7 64bit - I discovered that my Bios settings were marked as IDE for all drive ports, including the external eSata - this is really dull - speeds are hugely reduced, plus you don't get "Hot Swap" capability with external drive bays thru' the eSata port unless you are running in AHCI mode - you have to make sure AHCI mode is set in the system bios befeore you install windows or you're buggered - you need to set the bios correctly and re install - very tedious - except...
There is a way to safely enable AHCI mode. Be very careful in the
registry, failure to do this right, or damaging other registry keys
can and will terminate your system for good -
BEWARE - I accept NO responsibility if you screw up.
1. Start, type "Regedit" in search box.
2. Open HKEY_LOCAL_MACHINE / SYSTEM / CurrentControlset / Services
3. Open msahci
4. In the right field left click on "start" and select Modify
5. In the value Data field enter "0" and click "OK" (you may have a 3 as the value here)
6. exit "Regedit"
7. Reboot your computer and enter BIOS (hold "Delete" key while Booting)
8. In your BIOS select "Integrated Peripherals" , Now change SATA Mode from IDE to AHCI not forgetting eSata further down the list if you have it ,
9) Save and exit your bios - computer will re start - during post you will probably see the
AHCI drivers load and list your drives.