Help, cannot change permission on external HD

If the hard drive is from a PC it is probably formatted using NTFS. OS X can read NTFS disks but cannot write to them, that is why you cannot change permissions.

 

If your disk was being used under Windows, probably it's in the NTFS file system. If that's the case, you can't write anything to it, because that file system is read-only in Unix systems, including Mac OS X (thanks to M$, I might add). If you will use the disk only in Macs, I recommend you format it to the Mac file system (HFS+ if I recall correctly). If you need Windows compatibility, format it to FAT32, wich is the older Microsoft file system, and its read and write compatible with Mac OS X.

 

I wonder if this is still the case with Intel-based Macs.
If so, is it possible to save my files to my Mac, reformat the drive, and then put the files back onto the reformatted external drive?
Well, I guess I can move the files to my desktop, eject the drive, and then see if they are safe to use.

I did notice that my Mac cannot even recognize my hard drive with eight-year-old Linux formatting but can mount my external drive with SUSE 7.1.