hanks that worked.
after running explorer.exe from task manager i started norton anti virus
to check the system for infected files it detected a file named
"explorer.exe" in \\WINNT\SYSTEM32 folder which was an ad-ware/dialer
or some thing like that. It was also present in Temporary Internet
Files. I had to delete it manually by booting from windows 98 because
Norton refused to delete it by giving message "system file cannot
delete."
Problem it (virus or whatever) caused:
--------------------------------------
it Deleted all my dialup connections. i'm still not able to make new
dialup connections. cause when i give name to the connection it
starts giving error saying "name cannot start with a space", or some
thing like that.
still i'm starting it by ctrl+alt+del and then starting explorer.exe.