Using mac formated exernal hardrive on pc?

My girlfriend let me borrow her external hard drive so I could get some music from it but I've run into a bit of an issue. Her computer is a Mac and mine is a Pc. When I plug it into my computer the computer makes the noise as it usually does when something is connected via usb but nothing shows up when I go to my computer. I don't want to change the format of the hard drive only access the files. I might have to just use her computer but I'd rather not because I don't want to change he format of my iPhone.

A normal Windows PC will NOT read a Mac formatted drive. Your option for the PC is:
1) get the Mac user to create a drive partition that is FAT32 formatted
2) Load some third party software on your PC that can read Mac formatted drives, like Transmac:
http://www.acutesystems.com/scrtm.htm

Install HFSExplorer, free, to read and copy files from any Mac drive.
http://www.catacombae.org/hfsx.html (HFSExplorer, free)
http://www.oracle.com/...01631.html (Java needed for HFSExplorer)

NOTE: Does not actually mount the Mac drive. It works similar to recovery software- You have to launch the HFSExplorer app, and then it has its own window that shows all the files for copying from the Mac drive to the PC drive. It does not affect the Mac drive, so when you return it, Girlfriend will be happy.

It is possible to set up a Windows system to be able to fully mount a Mac formatted drive by buying MacDrive, TransMac or "HFS+ For Windows". These three are essentially equal in abilities.

She has several options (including free) if she wants to enable her Mac system to use an NTFS drive->