1. Open Notepad

2. Paste the following:
@echo off
SET /P PCNAME=Please enter your desired PC name:
REG ADD HKLM\SYSTEM\CurrentControlSet\Control\ComputerName\ComputerName /v ComputerName /t REG_SZ /d %PCNAME% /f

3. Save as Change PC Name.bat

Note: This requires administrative privileges.