windows can't read my HDD installed in my dvd slot on MBP I've swapped my dvd drive with an HDD drive on my MBP 2008 non-unibody.
I can read it from MAC os but not from Windows.
I did configure it to be PC compatible...

Anyone knows why it's not seen as an addtional hard drive?
"PC compatible" refers to the way, partitions are written to the disc, I think. If it is HFS formated, Windows does not recognize it. Have you tried to format it with FAT32?