[Mephisto]

The whole issue about copyright varies from country to country.
EULAs for example are widely not enforceable in the EU. Simply put, you already bought the software, the whole sales agreement was done in the shop (or where ever) and the EULA is just a try to alter this agreement. If you don't agree then the EULA will not become valid.
Clicking the "ok" button does not signal agreement. You own the software. You have already bought every right to use it. Preventing you from using the software before agreeing to EULA (and therefore altering the already existing agreement) is just blackmail.
Similar you have a right to copy software or music for your own use. You bought it. You own it. With ownership comes the right to do with a thing as you please (even destroying it). Preventing you from copying or selling it is interfering with your ownership.
Your right as an owner however is limited by copyright laws which try to balance the issue. Therefore you are only allowed to copy it for your own use, sell it if you don't keep a copy and prevent your from de-compiling it if the creator did not install program parts that interfere with your fair use.