You can copy the running config to a TFTP server, as well as the startup config.
From the enable prompt#
#copy running-config tftp
(means Copy the running config to the TFTP server)
#copy startup-config tftp
In both cases you will be prompted for filename and server IP.
#copy tftp running-config
#copy tftp startup-config
(Means copy a file on the TFTP server to the router)
If you copy the startup config, the router will continue to run as before until a reboot. Hence, if you have to change the configuration for a router, remotely a great way to do this is to use a TFTP server to upload a new startup config to the router, and then ask for it to be rebooted. For example, if the IP address is changing, you would lose touch with the router once you start the changes, but if you use this method you can keep in contact with the router until the reboot.)
A useful TFTP server: TFTPD 32 or 64. Free program
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