Can't save to external hard drive on macbook or imac

Hi,I am new to this so please excuse my ignorance. Recently purchased a Macbook and an iMac.
One problem - can't save onto an external hard drive when i use either. Have saved data on the external drive when i had a pc but cant use it now
All files are noted as 'Read Only' now and when i go to save it it says 'Do not have access to save'

Any suggestions?
Thanks

The external hard drive, is it formatted NTFS? If so, OS X (and really no other OS than Windows) can write to it natively. You'd need third party software to allow you to do so. The other options are to reformat it to a filesystem it can (FAT, HFS+)

Had the same problem over the past weekend. The fact is that the NTFS formatted external drives can only be read in Mac OS. Solution $20.00 and Paragon NTFS for Mac OS X.

Go to PARAGON Software Group - NTFS for Mac, communication channel between Mac OS X and Windows There is a trial version. Download it and test. It works like a charm.

Though I use pargon here is a possible free option

link

hi all thanks for the responses. will give them a try and get back to you. cheers