Unable to create a new user account on Vista

Unable to create a new user account on Vista.

Problem description:

When I try to add additional users, it never lets me finish the
process, recycling to the screen that says, "Choose the account you would
like to change"

The only way I have found to get around this is to use from the command line
the program name Netplwiz.

This will let you create and adminster accounts,
the regular gui interface does not work for any function of adding new or
modifying existing accounts on my machine either. To get to command line mode
, click the start button and immediately above it type in netplwiz where it
says "start search".