windows xp desktop showing blank screen on logon

[bsrinivas]

my system which has windows xp sp2 is showing blank screen with arrow cursor on logon. i used third party utilities and restored back to previous date. it was working fine. the next day the problem repeated. i repaired the windows xp installation but for no use.
does any one has the solution.

[dheeraj_kumar]

What did you install to get the problem first? and how long did do you get the blank screen before explorer loads?

edit: do you have zonealarm?