I need my windows product key.

[arashZ800]

hello there, I have lost my windows 7 product key label and formatted hard drive to install windows 10 but I need my windows 7 product key, so how I can retrieve my windows 7 product key?

[itsmyname]

@arashZ800 -- for Windows 7, there was a "decal" on the side/back of the computer case (or sometimes underneath the removable battery for a notebook type of computer) that showed the 25-character product-key. 

Or, if you made a retail purchase of Windows 7, you received a DVD and a printed copy of the product-key.

If you have "wiped" your disk-drive, or have lost that printed copy, you are "up the creek without a paddle".

You will have to access the online Microsoft Store to purchase a copy of Windows 10.

Some sellers on eBay may list something that is not 100% legal -- e.g., only a product-key, E-mailed to you.  I would avoid those sellers.