XFS is one of formats for Linux. Unless you have a third vendor software, you cannot read data from Windows PC.
If you format the hard drive by FAT32, you will be able to read from Windows PC. However, you cannot back up a file more than 4GB due to the limitation of FAT32.
If you have TeraStation III models, you may want to use "EXT3 Reader". With the program, you can read data on EXT3 formated USB drive from Windows PC.