Can’t find my Product key for windows 10 pro

Hi Mohammed. I'm Greg, awarded MVP for eleven years, Volunteer Moderator, and Independent Advisor here to help you until this is resolved.

Are you signing in with the same Microsoft Account you bought Windows at these sites to check:
https://account.microsoft.com/billing/orders/
https://support.microsoft.com/en-us/help/402731... ?

But when you buy WIndows 10 from the store it's a keyless Digital License that stores your hardware signature in MS Activation servers to compare whenever you reinstall. No key is ever required. In fact if you change the key from the default key present when you install Windows with no Product Key, it will never activate.

I hope this helps. Based on what you report back I can answer any questions and may have other steps to perform.

Yes I do but with an illegal copy of windows pro. How can I reinstall windows 10 pro with my recent digital purches. 

If you are not sure what all was installed with the illegal crack, you would be best off wiping the drive and doing a Clean Install following the illustrated steps in this link which include everything that works best in Windows 10: http://answers.microsoft.com/en-us/windows/wiki...

Make sure during the booted install to follow the illustrated steps to delete all partitions down to Unallocated Space to get it cleanest, then click Next to let it auto-create the needed partitions, format them and begin install - this makes it foolproof.

To create bootable Windows 10 Installation Media (on another PC if necessary) install Media Creation Tool and follow the directions in the middle of the download page here: https://www.microsoft.com/en-hk/software-downlo...

Insert media, boot it by powering up PC while pressing the BIOS Boot Menu Key for your PC maker given in this chart: https://www.sysnative.com/forums/hardware-tutor...

If the media won't boot you may need to enter BIOS/UEFI Setup (pressing key given in chart in link above) to turn off Fast Boot or Fast Startup first.

Choose the boot device as a UEFI device if offered, then on second screen choose Install Now, then Custom Install, then at the drive selection screen delete all partitions down to Unallocated Space to get it cleanest, select the Unallocated Space, click Next to let it create and format the needed partitions and start install - this makes it foolproof.

There is a step to rescue your files first using the booted media if you don't have them backed up: http://answers.microsoft.com/en-us/windows/wiki...

You will get and keep the best possible install to the exact extent you stick with the steps, tools and methods in the linked tutorial. It's a great learning experience that will make you the master of your PC because you will learn everything that works best and how to apply it with your own hands.

I hope this helps. Feel free to ask back any questions and let us know how it goes. I will keep working with you until it's resolved.

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Standard Disclaimer: There are links to non-Microsoft websites. The pages appear to be providing accurate, safe information. Watch out for ads on the sites that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the sites before you decide to download and install it.