Normally, installing software from a mounted ISO should not be a problem... certainly I've installed both Linux and Windows software from mounted ISOs and not had any such problem (but then again, I'm not using FC).
However, there are a few things I don't understand about your situation:
Originally posted by tom_from_van
Can someone please give me detailed instructions on how to mount a 2.6 GB, FC4-i386-DVD.iso file so that the desktop's "Add/Remove Applications" applet interacts with the iso and not with the cdrom (because it asks for install media of which unfortunately I have only corrupted copies).
1) You have an ISO.... I assume that this is the same DVD that you only have corrupted copies of. Why don't you just burn the ISO and use the new DVD to replace the corrupted one?
2) If the answer to 1) is that the ISO file you have was created from the original (now corrupted) media, then how do you know the ISO file is not also corrupt and that is the source of your problems?
3) If the answer to 1) is that this is a different ISO file than what your system is (you're acutally using FC3, and this is an FC4 DVD)-- well, just don't do that
4) This "Add/Remove Applications applet" seems to be kind of a problem... do you have an alternative to it (like using RPM directly, or apt-get, or Synaptic or Yum, one of which this applet is probably a front-end for)? The answer to your actual question is most likely that whatever package manager this applet is actually using needs to be configured to see the mount point of your ISO. Ah. A quick Google Linux
search takes me to the Fedora documentation on updating your software sources
, which reveals not only that you're using Yum, but also how to configure it.
So that should tell you how to add sufficient sources to either include the ISO mount, or make it obsolete, by adding external sources from the Internet, so that neither the corrupted media nor the ISO mount is strictly necessary to install whatever you're trying to install.
Hope this helps.