User account logs in but fails to display desktop

I set up multiple users using Rick for my desktop as the initial
administrator user. Early on I turned off User Account Control to avoid the
annoying and continuous requests for permissions to do virtually anything on
my own computer in my own desktop. I subsequently turned User Account
Control back on to facilitate the installation of a software program. After
rebooting the PC I was able to log on to Rick but after waiting forever found
that my desktop would not display. The only way I could display anything was
to use Ctrl/Alt/Del key sequence which then allowed me to switch to a second
user to reset the User Account Control to off. After rebooting I was able to
display the desktop for Rick. I since tried various settings changes to try
to recover from the loss of my desktop display while User Account Control is
in the on condition. After numerous attempts I am now no longer able to
display my desktop in either the on or off condition for User Account Control
even though I show that I am still logged in as Rick. How do a regain access
to my desktop display under user name Rick?