We do not have a compatibility lists on our I/O controllers and hard drives or SSDs.
The only thing that I see is that using a SATA III hard drive into a SATA II system may not be economically efficient, since anyway it will perform as a regular SATA II device, unless you are planning to change your laptop in the future and keep the driver with you.
Other than this, I consider that this should be fine. Try to chekc with Hewlett Packard* to see if that have heard of any compatibility issues being reported on their systems.
Okay, that's what I thought.
I was thinking of getting the SATA III one because it has 750 GB of storage. They unfortunately don't have a 750 GB model exclusively just for SATA II, the only SATA II they have is a 500 GB model. But yes, I suppose I could upgrade the motherboard in the future to use its full potential.
I doubt HP will tell me if anyone has had issues with other HDDs not in their list.
I've only heard of Momentus XT drives having problems with Mac notebooks.
Don't worry about what SATA your drive is and the max the drive supports. I don't think the Momentus XT 2nd gen can saturate SATA II's 300MB/ps bandwidth. The drive itself will be faster than the older Momentus XT due to basic mechanical improvements etc. on SATA II, probably even SATA I.
Just an update that I've installed the hard drive on here and it works like a charm.
The only weird thing that happened was when I first plugged the hard drive in it didn't work.
So then I unplugged the SATA cable from the laptop and plugged it back in and plugged back the hard drive back and then it worked.