Help! I accidentally deleted my administrator account and can't reset to factory settings!

yankeefan499

Honorable
Jan 20, 2014
2
0
10,510
Well, the title explains everything.
Hi, and thank you for reading.
I have a Dell Precision Workstation 690 that has frequent messages at startup saying "previous thermal failure", but thats not a big problem. The problem started when I made a new account called Guest, but deleted it and made a new account in my name. Further on, I changed that account to Administrator, so I had one standard user that was previously Administrator and an Administrator that was created as a standard user. Although, I didnt want that user anymore, so i deleted the Administrator user. I forgot it was administrator, yet it deleted so easily. Now, everytime i need Administrator permission, it shows "Guest" and has a password. Guest never had a password, so i dont know what to do there. If i leave it blank, it says "user not granted requested logon permission" or something like that. Ever since, i've wanted to find out how to fix it, but now i just want to restore it to factory settings. Ive tried everything, such as:

Trying to change the Administrator password or add an Administrator, but it says "system error 5 occurred, access is denied"

Tried to download those "file backup managers", but it needs admin permission


I really need this computer back to factory settings. What do i do??