1. Launch putty and connect to your Cisco router/switch
2. Enter the user exec mode (router> enable)
3. Enter the terminal length 0 command (router# terminal length 0) 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. Right-click on the menu bar of the Putty screen and select “Change Settings”
5. Go to Session and click on Logging, select “Log all session output”
6. Click on Browse and choose the location and name of the file (I like to place my config file on my desktop – C:\Documents and Settings\Administrator\Desktop\config.txt)
7. Click apply.
8. Now enter the show run command (router# show run), then log out and see the output in config.txt on your desktop (or the location you chose).
This is a pretty simple thing to do and can be a real life saver if you happen to lose the config on a device. It sure is a lot easier to copy and paste it back in instead of recreating it from scratch. Cisco equipment is great but I have seen instances where the running config wasn't saved to the memory and after a restart it reset back to an old startup config or back to brand new (worst case).
You now have the power!