Making ISO from ripped files

I have ripped many DVDs to a large hard drive while waiting for the blank media to arrive in the mail. I used DVD Decrypter in "File" mode. Only after ripping about 86 GB did I learn that I should be ripping using the ISO mode, which will help alleviate problems with freezing at the layer break.

Can I somehow create the ISO file from the DVD files, despite them being on my hard drive instead of the DVD itself? Otherwise, it's back to the video store...

 

You can use Shrink to make ISO.

 

Thanks. Is Shrink a stand alone program, or a subset of Nero?

 

You can download it here. Is a small, awesome free program.
http://www.mrbass.org/dvdshrink/
When you get to the backup part, you can choose to make ISO and burn with DVDDecrypter, make ISO and save to drive, or burn with nero.