Loss of operating system hp desktop

[lucky429]

I have an go desktop that originally had ms Windows 7 home 32 bit but had been upgraded along the way to win 10 64bit with2tb. So I don't know where it is best to restart. My issue is I can no longer boot up my computer due to it being hacked and now it tells me to install an operating system. I know it had been hacked because I was the only ower and administrator on the computer for last 2 prior years and it is a home comp with Password sign in. After the previous 2 years it suddenly went from administrator to administrator(s) plural. And then there started to show up other accounts allowed to control system other than the two(me and Guest )that were on it. Confused I started looking up how this was possible but mind you I am technical dummy but not stupid or without common sense and logic. Somehow whomever it was was granted a token access higher than that of owner and administrator. So apparently they had higher access than me(owner) somehow. In trying to do a recovery from an earlier point( which there should have been at least 5 at different dates) the system found none anymore and it kept getting worse til it could no longer find the operating system. Oh and I had also been locked out of my guest account which did not have a password as it was for company. So I need to get the correct is back in the computer but I'm not sure where to start. Or where or which is to use as it went from win7 32 bit to win 10 64 it with others in between as gradual updating occured over few years. And like I mentioned I'm not stupid but a technical dummy. Can anyone help? I need my comp. Can hardly read this 6 inch screen nevermind doing work on it. And very limited income. Disabled. Help?

[Prométhée]

hi

going back to the original windows 7 can be more complicated, you have to look for the dvds on third-party sites..
or if the windows key is still visible, find a windows 7 dvd of the same version, and activate with the key!
If windows 10 has been installed, you can use the microsoft media of windows 10 for installation, if you already had a microsoft account, then the activation must be automatic

https://www.microsoft.com/fr-fr/software-download/windows10

now, I don't understand all your explanation, but sometimes we think that when not at all..
If a computer is hacked, the hacker does not need to create another account..
if windows is now inaccessible you might have a whole other problem..
The computer must not be too recent, if originally with windows 7