Installing Win7 on a HDD setup for IDE mode in AHCI mode

[videobruce]

I'm not sure where to put this, but here it is.

Using a already formatted & partitioned HDD from a older non GPT ready (if you will) MB, I want to install Win7 64 bit using AHCI. The current O/S on that active partition is XP which I want to replace.
The other partitions (two) have data on them that I don't want to loose. (I do have it backed up).

What happens to the drive when I install Win7 in AHCI mode to the other non active partitions?

[videobruce]

A 2nd question; with a SSD drive that I have installed Win7 on (fresh install), for kicks & giggles, I switched back to IDE mode and booted back into Windows. To mu partial surprise, there was no difference unlike the other way around where you get greeted with a BSOD.

With that SSD, if I leave the SATA mode to IDE, what is the disadvantage?

[TheDutyPaid]

From what I found on Wiki, "Some operating systems, notably Windows Vista and Windows 7, do not configure themselves to load the AHCI driver upon boot if the SATA-drive controller was not in AHCI mode at the time of installation. This can cause failure to boot, with an error message, if the SATA controller is later switched to AHCI mode. For this reason, Intel recommends changing the drive controller to AHCI or RAID before installing an operating system. (It may also be necessary to load chipset-specific AHCI or RAID drivers — from a USB flash drive, for example — at installation time.)"

Think this would help, change the BIOS before install and not after.

[realstock]

More importantly, you need to have AHCI mode enabled to allow WIndows 7 to run TRIM. You should set this in the BIOS before installing Windows.

Tom's Hardware has a good link

Not enabling AHCI mode just means that housekeeping etc will not be performed on the SSD - linky

[videobruce]

I'm aware of that, but I also have a conventional HDD that will have a O/S on it also.

[brs]

As you are probably aware, Windows 7 does not have AHCI drivers. I have read that one work around is to install XP first, which has the AHCI drivers. Windows 8 again has the AHCI drivers.

[videobruce]

As you are probably aware, Windows 7 does not have AHCI drivers.

No I wasn't aware. From what I have read, it's a problem with the type od optical drive the O/S was booted from and/or the BIOS itself.