Cannot change anything in user account and family safety, even logging as an administrator account.

Question

My 1st user account was an administrator account, 2nd user account was a standard account. 3rd user account was a guest account of window 8 single language, however i accidentally made a mistake by setting guest account from standard account to become an
administrator account. I also set down the 1st user account from administrator to standard account and after these stupid settings, the guest account becomes administrator account anyone can access in without any password, the 1st and 2nd accounts become standard
accounts! Before this mistake, the 1st user account was the main account of mine, 2nd and 3rd (guest account) were logged in very rarely.
The problem is when i logged in guest account as administrator, i cannot set the 1st or 2nd back to become another administrator account. Something has gone strange, it has been prevented me to set the others to be administrator and the guest back to standard
account. Being as an administrator account, the guest account was totally useless in changing settings. When i logged in with 1st and 2nd account, i also cannot change anything in the user account settings (change type of user account) and family safety, all
attempts to change the user account settings was useless such as i never tried. I also tried "refresh your computer without losing files" but not worked. Please provide me some advices!
I did not find the forum for win 8 single language, so i place my question here.

Answer 1

Thanks for your reply. I tried to go to safe mode of win 8 by holding the shift key while clicking "restart" on the login screen. (My login screen now shows 3 account users). Then i chose troubleshoot -> advanced options -> windows startup
settings-> i went to safe mode. The safe mode only showed a complete black screen with an only window: "Administrator: cmd.exe". I did as you said (typing NETPLWIZ) and the User accounts window appeared. I went to "properties" of each
user account and set 1st and 2nd accounts to Administrator but got the error: "This user cannot be added. Access is denied." and another error window: "Usert accounts: the group membership for ... could not be updated."
Yesterday, i went to elevated command prompt as an administrator and typed "net user administrator /active:yes" with hope that the built-in administrator would be activated and i would use it for full control settings of 3 other user accounts.
But i got the error: "system error 5. Access is denied."
Now, my position is quite bad. Login with guest account which was set as administrator, i still can not have full control of this laptop, so that all attempts of mine to change the user account settings is denied. This guest account also does not have a
password at all so that everyone can open my computer without typing a password. Because access is denied, i cannot set a password for the guest account even now it is the administrator account and i am loging in it.
p/s: I tried to refresh the system but still got the error: "There was a problem refreshing your PC. No changes were made". And i also tried to restore the system, but got the error: "System restore did not complete successfully. Your computer's
system files and settings were not changed. Details: A volume shadow copy service component encountered an unexpected error. Check the Application event log for more information (0x80042302)"
I went in registry editor in safe mode and did as you said but there was no "AutoAdminLogon", "DefaultUserName", "DefaultPassword". I only saw "AutoLogonSID" and other different names...
The problem i got half year ago has still remained and recently i made this mistake. https://social.technet.microsoft.com/Forums/en-US/8ebd868c-bdfd-412e-95a6-9dc0095d431c/cannot-paste-any-online-pictures-from-any-websites-into-wordpowerpointonenote-2013?forum=officeitpro
I am a young woman who always creates mistakes when setting computer because of my carelessness.
Hi,
These phenomenon should be access rights problem, you need to check your current system User Accounts status. In my opinion, your administrator account probably disabled.
Open Run, type LUSRMGR.MSC, press Enter.
Then check your current system account which Group they are belongs to.
If there is any progress, please feel free let me know.
Roger Lu
TechNet Community Support