Failed Win10 upgrade - do i need to reinstall?

[Charles_2007]

I grabbed from work an old Thinkpad T420 computer with win7pro activated,  It doesn't have the COA certificate on it

 

I removed the mechanical hard disk and started a clean install with Win10 on a blank SSD

 

I was hoping that the activation would carry over on Microsoft site but it did not work

 

Before I go to extreme measures, is there any way to extract the activation key from the old hdd?

 

If I put back the old mechanical HDD,  will the upgrade to windows10 need the COA? 

 

 

[Master Disaster]

Put the old HDD back in, fire it up and use one of the hundreds of free Key Extractors available to recover the 7 key. Swap the new drive back in and assuming you installed an equivalent version (7 home to 10 home or 7 pro to 10 pro) Windows 10 should happily activate using your old key.

[Radium_Angel]

9 minutes ago, Charles_2007 said:

I grabbed from work an old Thinkpad T420 computer with win7pro activated,  It doesn't have the COA certificate on it

 

I removed the mechanical hard disk and started a clean install with Win10 on a blank SSD

 

I was hoping that the activation would carry over on Microsoft site but it did not work

 

Before I go to extreme measures, is there any way to extract the activation key from the old hdd?

 

If I put back the old mechanical HDD,  will the upgrade to windows10 need the COA? 

 

 

Yes, you can extract the key with a program called produkey

The win10 install *may* accept the Win7 key, depending on what type of key it was (OEM, retail, etc)

[Charles_2007]

I tried Produkey and et was deleted by the antivirus software

 

I disabled the antivirus and installed it again; it successfully located a windows 7 pro product key from the Windows registry hive files from the old drive with a sata to usb3 dongle

 

Microsoft did not accept that cd key.  After looking around, I found the original windows7 pro  product key inside the battery compartment,  after using it.  it successfully activated my win10 pro installation on this laptop.

 

Funny thing,  I built this old laptop as a spare computer for the office and after about 2 hours somebody came to my office begging for a spare computer and the computed was sent to an external job the next day.