1. Make sure you are connected to cisco switch via console cable or network cable. Open Putty. (if you dont have putty you can download it from here - http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html
If you are already connected to cisco switch via Putty then follow below steps.
2. (Right click) Go to change settings > Session > Logging > select ‘All session output’. Then type file name and path. Apply.
3. Login to switch. Issue the terminal length 0 command in order to force the router to return the entire response at once, rather than one screen at a time. This allows you to capture the configuration without extraneous --more-- prompts generated when the router responds one screen at a time.
4. Type sh run, this will display configuration and save config in file.