Windows loopoing with circle going around

I know lots of people have had similar problems some successfully fixed others possibly not anyway here is my scenario. Just come into possession of an Asus desktop AMD cpu 8GB DDR3 and 3TB hdd. Been told was reset before being handed to me. Anyway on booting all I get is the dotty circle going around with the message wait a moment. Well I have waited more than a moment in fact over an hour and it does not change. Managed to get into safe mode but can only find reference to one program which is the realtek audio one see,
ms to be devoid of everything else. Eventually got it to try and repair itself with usual messages ie loading files this percent that percent all seemed well until I restarted as commanded and yes circle again. Have tried a reset again that failed after about 5%. Trying to delve into it more it asks for the administrators password been told never was one.
Read that if one gets to the command prompt to type

net user administrator /active: yes This I succeded in doing and it was happy with that command.

Not that it has got me anywhere as is still asking for a password.
Spent hours on this. Even tried to do an install of windows 7 from DVD and that just looped with the logo on the screen. Grasping at straws I have unplugged and replugged everything with no joy. What confuses me is the failure of both win 7 and 10.
Any ideas? Thanks

Are your files backed up?
Had you made an image of the drive?
Do you want a clean install of either Windows 7 or windows 10?
Is the operating system a genuine copy of windows?
Does the computer have any history of hardware or software problems?

Power on the computer and repetitively click the F2 or F10 key. Open the bios UEFI diagnostics.
Many HP computers come with UEFI diagnostics from the factory. They are available on line for free. Or they can be downloaded when you log on to HP, enter your product or serial number, enter operating system, and view available drivers and applications.
So the studies that you can perform now depend on which version of the UEFI is on the computer.
If you can run the UEFI diagnostics in extensive or loop until failure mode you can check the hardware, especially the drive.
Do you know if it is a HD or SSD or the manufacturer?
Which operating system is on the computer now? 7 or 10?
You have HP recovery media? One DVD for the OS and one DVD for applications and drivers?
Create a bootable windows 10 iso: Download Windows 10
If you can boot the computer to the desktop the open file explorer and insert the windows 10 iso into any flash drive.
In file explorer click on this PC, then find the USB drive and click on it.
Look for setup or setup.exe
Click on it and view the left lower corner where it displays repair.
Click on repair to perform an in place upgrade repair. This should save your files and applications.

If you cannot boot to the desktop or open file explorer then insert the bootable windows 10 iso into any USB port.
Power on and repetitively click the F9 key so that it displays boot options.
Select the external disk drive.
It will take 5 to 10 minutes for windows to load while you see the windows icon.
Choose language, time, currency, and keyboard.
Do not click install as this will lead you to a clean install. Unless this is what you want.
If you want clean install then delete partitions, format the drive, make it an unallocated drive, then install windows 10.
For the repairs view the left lower corner and click on repair.
Then navigate the windows recovery or advanced troubleshooting menu and start with restore. See if there are any valid restore points that predate the computer problems. If not or if restore fails move to startup repair. If startup repair fails move to command prompt. If you are at this point let us know in the thread.

My what an exhaustive answer how very kind. Will try your suggestions later today. As regards some of the questions you have asked no there are no backups the previous owner did not believe in that! It is a genuine copy of windows10 home came installed with the desktop. Supposedly doing a reset which was done before handing over to me put the machine back into the state it was on the date delivered but patently not in this case. Iwill be happy to run windows 7 on it if needed using my windows7 cds to get it on there.
Regards

You have HP recovery media? One DVD for the OS and one DVD for applications and drivers?
Create a bootable windows 10 iso: Download Windows 10
If you can boot the computer to the desktop the open file explorer and insert the windows 10 iso into any flash drive.
In file explorer click on this PC, then find the USB drive and click on it.


Bit confused as not HP but ASUS desktop. PLus cannot do any of suggestions as cannot get into system.

On this web page if you view your entries there is a section "my computer".
In this section you have entered HP laptop win 10.
Please update this information with as much detail as possible about the computer that you are troubleshooting.
All of the information in post #2 was based on the information that you had under "my computer".
For recovery media you have windows 7 and that is an option in case you prefer that operating system.
Having upgraded to windows 10 during the free period you should be able to perform a clean install using the bootable windows 10 iso. As any upgrade during the free period created a digital license.
Which do you prefer widows 7 or windows 10?
Both will be clean installs as you do not have any important files.
The clean installs remove corrupted operating systems/registry, files, and applications.
Starting with a clean install will save you a lot of time troubleshooting.
Each computer manufacturer has a F key to boot to the bios.
List of PC brands with their corresponding hot-keys
For Asus it is the F8 key.
Have you created the windows 10 iso?

Sorry if I confused people but I did state the computer I was having the problem was an ASUS desktop. Anyway problem solved. Borrowed a recovery disk and made up an administrator password though no idea why I had to as one was not set originally.