I bought a new computer yesterday and need to install microsoft office 2007 but i have no CD?

I have the product key but i lost the CD and my new computer says i need to install microsoft 2010 but i have 2007 and when i type the product key for 2007 i wont let me use it it says this program is too hold HELP me I don't want to spend another 60 bucks can u guys tell me how to install it and what can i do im not looking forward to buying a new MICROSOFT office sorry for any spelling errors my grammar is not that great.