Vaio laptop VPCCW19GX - upgrade to SSD?

I have a 4 year old Vaio laptop, Model: VPCCW19GX. It's running Windows 7 Pro SP1 on a Hitachi 500 GB HDD. All is working fine with this rig and I really only use it to browse and have as a portable when I'm helping friends and clients with their PCs.

With the price of SSDs plummeting, I thought it would be nice to upgrade to a SSD and improve the performance. If you catch it on sale you can get a 120 - 128 GB SSD for around $70. This would work fine for me as the total used space currently on the Hitachi 500 GB is about 69 GB.

Here's the problem. I checked that TRIM is enabled for the laptop and it is. I checked the registry and in there the msahci value is set to 3 which means that AHCI mode is not enabled. That makes me think the Hitachi is running in IDE mode. Of course going into the BIOS gives you absolutely no options to view/set the SATA controller to AHCI/RAID mode. From what I understand about SSDs they will run in IDE mode but lose most of their performance advantages and also their longevity might suffer.

I know I can do the registry hack and change the msachi value to 0 which would enable AHCI and then reboot. Windows should then install the AHCI drivers and I should be good to go. Except I have no way to check if the SATA controller in the BIOS is set to AHCI/RAID.

Plan would be to pop out the old HDD, pop in the SSD and use the full set of Recovery discs that Sony sent me when the previous HDD crashed to restore to the SSD. I spoke with Sony Premium Support and the tech (after checking with someone who knew what I was talking about!) said Sony does not recommend using a SSD on this model.

Does anyone have any suggestions as to how I could make this work? For a $70 investment it would be nice to enjoy the greatly increased performance offered by the SSD.

TIA for any replies. :hi2:

Edit: I did manage to determine that it looks like the AHCI driver is installed through Device Manager. Please correct me if I'm wrong.