Lost sticker with product key - Windows 7 OEM re-install on new HDD

[lttlwlf]

Hello,
I had to replace my hard drive. I re-installed my copy of W7 (OEM) on the new one with the CD I got from the store. But I lost the sticker with my product key. I still have the CD + the proof (invoice) that I bought this copy of W7 legally. The hardware in the computer is exactly the same except for the HDD.
By the way, it's a computer I built myself, I bought all the parts and the copy of Windows from the same store (in case this is relevant).
What can I do ? Thanks

 

[bignastyid]

You need the key, If you lost it you'll have to buy another.

 

[simonchipmunk]

install Belarc Advisor. it is free and it will find the product key for you. Jot it donw and keep it in a safe place.

 

[bogdansv]

As simon pointed out you can see your license key installed on the old hdd. So connect the old HDD and run an audit with belarc advisor or the simpler ProduKey from Nirsoft http://www.nirsoft.net/utils/product_cd_key_viewer.html. Write it down and reinstall on the new HDD using the KEYS found.

Another option is to alltogether clone the old HDD data to the new one. (Clonezilla and Acronis True Image come to mind and you should watch a Youtube video to learn how to do it first. Make sure your source and destination are correct as you can delete everything if not careful.)