Cant Create Users... need help real bad...

Im running windows 8, and i have encountered a problem that i can seem to fix.

my problem is that i cant get any other user i create in windows to display in the user select screen.

in control pannel in the user options it shows that i have created multiple users, but for some reason i can not get access to any user other then the original one i set up when i formatted.

i hope i have explained my problem well enough.
please if someone could help...

By any chance did you use any kind of registry cleaner ??? Some registry cleaner can "Really clean your registry" and make users list inaccessible.

my buddy formatted my computer, and yes he's really into that type of stuff so i would not be surprised.
is there anything that can be done to fix it?
im guessing at this point another format.
but im really tying to avoid that

One thing I know for sure is Windows 8 Manager from Yamicsoft Registry Cleaner. It cleaned tons of registry entries and after that I can't switch to any account but I've always been cautious to backup the registry before I mess around with registry. In addition, I've always kept at least 2 image backups so I can go back to earlier copy. One thing you could try is to do a System Restore to see if it fixes the problem.