Windows 10: How to get a product key from a previous install of windows?

I am unsure of how to do this, but how do I get a product key from a past install of windows? The install was of Win 10 Pro I am running 10 Home now, I still have the drive it was installed on but the hardware has changed. Does anyone know how I can get the key from that past install to activate this one?

:)

 

windows xp installation and dual core am

could someone please list the steps they follow to install windows with a dual core processor and windows xp service pack to. I'm reletively new to amd dual core and i feel i'm missing a step. All help will be appreciated. thanx

 

Windows Product Key

A friend of mine has an all-in-one that came with Windows 8 pre-installed. He erased the original OS thinking he could install another version of Windows 8. One thing he encountered, that he didn't expect, the BIOS/UEFI has a password. So, basically he is locked out from installing another OS. His BIOS has the product key nestled inside. Is it possible to find out which version the product key belong to?

 

Clean Install Workaround for Vista

You may remember this news story on techPowerUp! a couple of days ago relating to the lack of clean installs when using the Upgrade Editions of Vista, which required an old OS to be installed. However, Paul Thurrott has managed to find a workaround for this issue, which ironically lets users do a clean install Vista without any previous version of Windows, albeit a little tedious. Here are the steps:

• Boot from the Windows Vista Upgrade DVD as normal
• When prompted for a product code, leave this blank
• Select the version of Vista you have purchased and let Vista install
• When you boot to your desktop for the first time, run the Vista setup from Windows
• This time enter your product key
• When asked whether you want to do an Upgrade of Custom install, select custom and choose a clean install
• Windows will now install for a second time and you should be able to activate it

Remember, these steps are only advised for use in order to achieve a clean install of Vista, it is only legal to use the upgrade editions if you have previously purchased the appropriate version of Windows.

Source: DailyTech