We pay all our bills off the wifes puter electronically. Her dell booted up to the password screen and it dosen't have any user accounts listed so you can't do anything. She has never used a password. I cont alt deleted 2x and it went to the admin login screen and it won't accept anything there either. I reloaded windows, came up the same way, and used the shift =F10 to get a command prompt, typed in nusrmgr.cpl to access the user group and it was blank, there were no accounts there, not even admin. What now?
If you've already reloaded windows on the same partition that it was already installed on without formatting, then you have one of two things:
An option on startup to select from two different operating system, or you've over written the other, and those user accounts are gone. Some of the folders and files may still exist, but you aren't going to have the option to select the previous user accounts anymore.
Long story short, sorry about your loss, good luck on the rebuild.
Create a PE disk with a password reset tool on it. Boot to the PE disk and look for all of your data by browsing the hard drive. Hopefully, none of it got overwritten. Use the password reset tool to reset the admin password.