Using a Mac formatted E-Sata hard drive in a pc?

Recently, my girlfriend took her laptop into Best Buy. It's a Toshiba satellite (the same model I have, but mines a more recent model) When she bought it, she bought it at best buy, since she worked there and got a nice discount, she also bought the two year warranty with it, where best buy will fix it free of charge, parts and labor, if anything goes wrong. Recently, we were testing a minecraft server that we were setting up, and she kept hearing a clicking sound. After a bit of research, I found that's usually a sign of a hard drive going bad, but it could also be seated improperly. I popped it open and took a look. The hard drive wasn't seated properly, it wasn't put into the metal frame correctly, and wasn't getting a good connection with the drive. I also noticed that it's formatted for Mac, it has the logo right on the drive. I'll admit, I'm somewhat out of the hard drive scene, software is more my specialty. I'm assuming this means it's formatted into FAT32 or something similar? Will that make a difference as far as performance or drive life goes? Should we go back and have a different drive put in? Just curious and was unable to find a lot of info giving me exactly what the differences between mac and PC formatted e-sata drives were. Any help is always appreciated...

thanks in advance
- Jason