Big problems windows 10

Hi
Yesterday i wanna start my computer and i wanna log in but all my passwords changed.
That problem i solved myself but now that i'm logged in i cant install programs or delete programs.

My pc is so slow now and i did a virus scan but nothing found!
I wanna reinstall windows 10 but even that i can't do something is blocking everything!!

Pleas some help ?

Sorry bad english.

Sounds like you got yourself on a non administrator account does it ask for a password when you try to install a program or delete program.

No i'm on admin account it dont ask for password when i try to install a program it says a error because it can't write to registery! but i just wanna reinstall to factory settings but i did everything i could think of

Windows 10 installation cd
Windows 10 installation usb
Systemrestore
...

But everything fails

Thanks for your time !

So you cannot clean install from USB or DVD during boot-up?

enigma101 said:

So you cannot clean install from USB or DVD during boot-up?

i solved it ! The only solution whas to put the hdd in another computer as a second hdd and format it.

Shawkeee said:

i solved it ! The only solution whas to put the hdd in another computer as a second hdd and format it.

Probably the safest way. We'll never know now, but my guess is that some malware had blocked access to the registry. A format would have wiped that clean.