Open regedit,
And drill down to
hklm\software\Microsoft\windowsnt\currentverson\profile list Expand profile list and highlight the guids one by one.
if u find
c:\users\Admin in the right pane while highlighting any one of the sid rename it to .bak.
Say in my case if i highlight the first long sid it shows my profile path in the right pane. So this sid is belongs to my login. Like this you have to rename
Admin's sid.
Rename the long string to
admin.bak. Restart your computer and try