Is it legal to sell backup copies of computer software (in online auctions or on website)? Is it legal to buy and use a backup copy of software I already own?

There is no other provision in the Copyright Act that specifically authorizes the making of backup copies of works other than computer programs even if those works are distributed as digital copies. It is also important to check the terms of sale or license agreement of the original copy of software in case any special conditions have been put in place by the copyright owner that might affect your ability or right under section 117 to make a backup copy. You are not permitted under section 117 to make a backup copy of other material on a computer's hard drive, such as other copyrighted works that have been downloaded (e.g., music, films). Under section 117, you or someone you authorize may make a copy of an original computer program if the new copy is being made for archival (i.e., backup) purposes only you are the legal owner of the copy and any copy made for archival purposes is either destroyed, or transferred with the original copy, once the original copy is sold, given away, or otherwise transferred. This privilege extends only to computer programs and not to other types of works. Although the precise term used under section 117 is “archival” copy, not “backup” copy, these terms today are used interchangeably. Yes, under certain conditions as provided by section 117 of the Copyright Act.

Personal backup copyright protection