First I’m sorry for not spending time to update and also answer to your questions, but I’m very bussy (going to military service!!!), but this one is from my brother Komeil Bahmanpour http://www.komeil.com
While you’re trying to update your phone, you’ll disappointedly observe the following error:
"Nokia Service Layer Host Process has stropped working.
CAUTION: Do NOT detach the phone from USB! Doing so, you’ll loose your phone’s functionality.
Open Task Manager and find the file for "Nokia Service Layer Host Process" named "NSU_UI_Client.exe".
Kill its process.
Start the same process again.
Focus to Nokia Software Updater’s interface and search for your phone.
It’ll show you a message indicating your phone was disconnected during the update process.
Press Retry. You’re saved!