Not sure the answer to your question but one alternative might be to get the free download of Open Office.  I has the same modules I think as MS Office.  Plus not sure whether MS Office 2007 has the capability to save a Word doc as a pdf but Open Office does.  I think I found a link to download it from the Firefox website. And you might go ahead and get open office and then later if you still want MS Office you can go ahead and figure out how to get it, but could use Open office in the mean time.  it seems to be pretty compatible back and forth with Office 2003.  The interface is a bit different but basic functions are pretty intuitive. i  haven't gotten into figuring out other functions since i mainly used it to save word files as pdfs.
I had to reinstall my OS several months ago in association with a fried motherboard. Everything on my hard drive got recovered.... except for my installation of Office 2007. I had a fully activated installation that had shipped new with my computer, but I somehow managed to lose the install disc that came with it, so now i'm stuck without it. I've hunted around the microsoft website to see if there's a place to redownload it, but can't seem to find one that remembers me. Is there a way for me to recover my product key from dell to activate the trial version, and if not, where do I need to go to order a new install disc?
Microsoft Office 2007 Reinstall