I need an application to split and iso disk image into mutliple parts

well today i bought a usb 16gb flash drive to some iso files from one computer to another only to realize that it was pre formated in fat 32 which i found out earlier from another thread that it won't copy files that are over 4gb. So for most of the movies i was able to 7zip it before to under the 4gb line. But i one of the files only compressed like 20mb out of 4.4gb on ultra compression, which seems a bit odd so i guess i'm stuck and i just need to split the image so i can get it on the drive, and you know reassemble it when i get it to my other computer. So any free application suggestion would be much appreciated