Where can I purchase Windows 7? Preferably Ultimate.

My new laptop came with Windows 8, which I hated. I upgraded to 8.1 and I no longer hate it but still really don't like it so I would like to go back to 7.

Unfortunately Dicksmith took my old laptop when they gave me credit for the new one and the hard drive they sent back doesn't work so I can't pull the key from there either.

Is there any stores in Hamilton or Online? I checked TradeMe but could only find a disc with no key. I'd really like a clean install as well, I'm really tired of all the bloatware.