Discussion:
Subject "A" has a full version of a particular computer program/software utility (Say version 2.0 for argument). However, it is an older version and he has since upgraded to version 3.0. Version 2.0 can no longer be purchased on the open market.
Subject "B" is in an identical situation
Subject "C" wishes to buy this program (version 2.0) because he does not need the full function of version 3.0 and his computer does not meet the minimum hardware requirements of version 3.0.
Both Subject "A" and "B" are willing to part with the older version of their software. Subject "A" is willing to sell it and subject "B" is willing to give it away.
Are either of these transactions legal and under what conditions?
Thanks

Answer:
I'm not quite sure the full extent of the situation. Under copyright, if they no longer used the version 2.0 on their machine, then the software's legal to transfer as you see fit, as long as you transfer it physically (on the disc). One disc, one copy on that disc.
However, if the provisions of use of the version 3.0 was upgrading from 2.0, then you must still have a legal version of 2.0 to keep your version 3.0. I believe this is 100% in software because of licensing, not because of copyright.
Check your user license agreement and whether you are required to have an earlier version of a software in order to legally own the new version.