thanks blacklotus for reply.
Yes, I can log in my user normally. I am not getting any screen messages on startup.
I am just seeing this message in event viewer in system part whenever system starts but secong forgot to mention is I am also getting error messages consistantly in application part of event viewer,
Event Type: Error
Event Source: Userenv
Event Category: None
Event ID: 1500
User: NT AUTHORITY\NETWORK SERVICE
Windows cannot log you on because your profile cannot be loaded. Check that you are connected to the network, or that your network is functioning correctly. If this problem persists, contact your network administrator.
DETAIL - Incorrect function.
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp
I had changed my AV from Avast to Nod32 befor a week.
It may be due to this, because I am getting this messages after changing my AV.
I had also download UPHclean utility form Microsoft site, but messages are still coming.