HELP HELP My system Logs off AUTOMATICALLY

Hey guys I need UR help

I have win xp prof with sp2

My PC seems to have a problem

I am able to boot properly but when I reach the logon screen and click on the username the message appears under the username

:::loading personal settings:::

followed by

:::logging off:::

In other words my PC does not reach the main windows interface but logs off AUTOMATICALLY before even logging on.
I can able to boot in safe mode but not in normal mode