I thought that a custom (clean) install was what created windows.old, if the old OS partition wasn't wiped (reformatted) first. I haven't done it myself - I always imaged the partition, and reformatted as part of the install.
It doesn't really matter whether windows.old is there or not. I doubt that the Roxio software is the sort that can run without having been installed (registry entries, files in special locations).
If you have a commerical PC (HP, Dell, etc.), the Roxio stuff was pre-installed, and you have no install media for it, it's effectively gone if you wish to stay with Windows 7.
Windows 7 supports CD and DVD burning to a greater extent than older versions of Windows, and there are freeware burner packages available. (I haven't used them.) Or, you could always buy the Roxio stuff again. (Make sure whatever you get is Windows 7 compatible, though.)