Ok so here it goes. The situation I'm in is pretty akward and it's quite a long story but I'll try my best to explain everything. This afternoon I went to a friend's house to transfer some data to my external hard drive (MyBook Studio). Since my HD is formatted as HFS+ and my mate owns a Windows PC, I'd asked him to install MacDrive. When we plugged in my HD, Windows just didn't detect it. We tried all sorts of things, including rebooting.. but nothing seemed to help. No matter what we did. The damn thing just didn't detect my hard drive. Not even with MacDrive. I desperately wanted to transfer some data to my HD since I'd drove quite a while to get there. So after a bit of Google research we decided to create a partition. My HD has a capacity of 1 TB and only about half of it was being used. So we went on and created a NTFS partition of 400 GB. Now Windows could detect the partition we'd just made. Everything went fine, we could now transfer some data to my HD. Nevertheless.. when I got home and connected my HD to my Macbook Pro, Finder could only see the partition which we formatted as NTFS. The other 600 GB, which we hadn't touched.. is nowhere to be found. There's quite a lot of important data on there so I would really appreciate it if anyone could help me. Thanks in advance.