sometimes desktop will not open?

[macbak]

Maybe 1 out of 10 time i power on my computer, when windows starts my desk top will be blank..no task bar, no icons nada, i have to ALT-CRTL-DEL to open windows task manager then go to file, run and type in explorer for the desk top to populate..

Using win XP pro.
any ideas on what my issue may be?

Thanks
Mac