Help - New to iMac

[MacDenver]

Just bought a new iMac. Love it but am having an issue trying to copy photos from the CD Rom I have inserted to a Toshiba 593400-A 500GB Drive I own. I am trying to transfer photos to the Toshiba drive so I can view them on my Lenovo Laptop (which does not have a CD Rom Drive local). When I try to copy from the CD Rom it simply won't allow me to do so. I can copy to the desktop, into iPhoto etc but not the Toshiba drive. Any ideas?

 

[cradom]

If the Toshiba is formatted NTFS it is read only, you cant write to it unless you use something like ntfsMounter.
In order for it to work on Windows and OS X it needs to be FAT32.