[discostu]

All the stores (at least the ones I've dealt with) are taking that policy with digitally copyable stuff (DVDs, CDs, and CD-ROMs). The excuse I've heard is copy right law which I'm not sure I buy but I am sure that touches on why. My guess is that you can copy stuff for so cheap and leave no evidence of ever having touched it (unlike analog stuff like videotapes) that they're afraid of getting scammed (buy the software and a blank CD, copy the software to the blank CD, return the software, keep the blank, brand spanking new software for $1). Knowing how this stuff goes somebody probably got scammed big time before they figured out they could be.

[Bloody Sam Roberts]

The only thing I can think of is that the manufacturer will NOT take it back from retailers as defective once it is opened. Otherwise, Walmart and others would take it back from consumers.