Since i booted PC hard drive led is always on and i hear hard
drive activity, i closed all programs i could, but its still
reading or writing to hdd.
What program can tell what process is using HDD right now?
Check out FileMon, from Sysinternals:
"FileMon monitors and displays file system activity on a system in
real-time. Its advanced capabilities make it a powerful tool for
exploring the way Windows works, seeing how applications use the files
and DLLs, or tracking down problems in system or application file
configurations. Filemon's timestamping feature will show you precisely
when every open, read, write or delete, happens, and its status column
tells you the outcome. FileMon is so easy to use that you'll be an
expert within minutes. It begins monitoring when you start it, and its
output window can be saved to a file for off-line viewing. It has full
search capability, and if you find that you're getting information
overload, simply set up one or more filters."
http://www.sysinternals.com/Utilities/Filemon.html