If you have a legitimate, unused retail CD and simply lost the sticker, you have three options—none of which involve finding a free "list."
Here are free, safe alternatives that open .docx and .xlsx files perfectly: ms office 2007 product key list
Sometimes the issue is not the key, but the activation server. Because Office 2007 uses SHA-1 hashing and TLS 1.0, modern Windows 10 and Windows 11 often cannot connect to the old activation servers. If you have a legitimate, unused retail CD