Rules on returning software that was bought online

I purchased a Windows XP cd online but it turns out i don´t need to install it. I would like to return it but i cannot seem to get through to the service department of the sellers and get a reply regarding how, if or when i should return the cd. What are the rules if any regarding the return of goods purchased online and specifically software?

Software is OUTSIDE of the distance sellings regulations so you DO NOT have the automatic right to return within 14 days. You are therefore relying on the good grace of your supplier. If the unit is 100% sealed and unopened then they may well accept a return if you ask nicely, but if they tell you to bugger off you are stuffed.

If they won't give you your $ back, try directly with Microsoft. If all else fails, flog it on Ebay...