Recovery

[Jay_07]

I was an windows 8 RTM professional OEM:DM user 

after launch of windows 10 i purchased windows 10 pro but now it lags like hell i want to go back to my old windows 8.1 version. I tried to install windows 8.1 single language but it shows product key as invalid 

PLZ HELPPPPP

[Prométhée]

hi

if you had original windows 8 pro, you should be able to reinstall the same version!
No need to indicate the product key, at the time of installation which is registered in the bios

you must therefore obtain a windows 8 pro installation media if this is the case!

[Paul_Tikkanen]

Hi, @Jay_07 

According to the product specs your notebook came with W8.1 'Standard,' not W8.1 Single Language.

HP 20-r012in All-in-One Desktop PC Product Specifications | HP® Customer Support

According to the parts list for your PC, it came with the option of W8.1 'Standard' or W8.1 Pro, and apparently yours came with W8.1 'Standard,' according to the specs.

HP PartSurfer

Go back and download the plain W8.1 64-bit ISO file and use that to reinstall Windows 8.1.

The file will work for either Windows 8.1 'Standard' or 'Pro," so you are good either way.

Download Windows 8.1 Disc Image (ISO File) (microsoft.com)

As Prométhée indicated, if you are installing the correct version of W8.1, you won't even be asked for a product key.

I have zipped up and attached the Microsoft tool you can use to transfer the ISO file to a DVD or USB flash drive so that it is bootable, or you can use the free Rufus utility for that.

Rufus - Create bootable USB drives the easy way

After W8.1 has completed installing, you can install the drivers and available software from your PC's support page.

HP All-in-One - 20-r012in (ENERGY STAR) Software and Driver Downloads | HP® Customer Support

[Prométhée]

Hi thanks @Paul_Tikkanen  your answer makes me ask a question
I had not checked, if the computer was delivered with a pro version
When I read the OEM version, I thought it was the stock version.
If we install from an iso file, and we give our product key, then it should be OK..
But @Jay_07   you said here

"I tried to install windows 8.1 single language but it shows product key as invalid  "
is that what you ended up trying?
is it the key for the pro version that you indicate and which does not work?

Where did your windows key come from?
Maybe you can only reinstall the original version, so without using the pro key!?

Now just a personal point of view
Drivers for windows 10 are available
The computer, should be compatible..
And to have also used windows 8, it seems to me curious to have problems with windows 10, which is much more user-friendly and stable than w8!
But if it is original, your problems could be related to this

• Amount: 4 GB
• Speed: PC3-12800 MB/s
• Type: DDR3-1600

and

• Size: 1 TB
• Interface: SATA
• Rotational Speed: 7200 rpm

So even with windows 8 it's not extra!

a little complicated with an all in one
but 8 gb would be better, as well as a sata ssd instead of a hdd, could give it a little more reactivity