A useful tool to automatically back up your running-config is the Archive tool set.
Part of Cisco's Archive and Restore features it allows you to take the running-config and archive on to either that device or to a remote device such as a tftp server.
Set up an Archive using the following:
R1(config-archive)#time period 10080
In the above you set the destination server, the $h indicates that the archive will automatically be called [the host name of the router]-1.txt. The next archive will be [host name]-2 and so on...
Write-memory prompts the archive process to run every time write-mem is executed and the time period is set in minutes to automatically execute an archive backup.
So you now have your archive running. Next you decide you need an archived config to be restored.
You 'could' perform a #copy tftp run but remember that this will only merge the saved copy into the running config not totally over write it.
You 'could' perform a #copy tftp start but that would require a reload to restart the system and boot using the startup-config.
To immediately install an archived config perform a replace:
R1#configure replace tftp://10.10.10.10/r1-1.txt
What then occurs is the router compares the archive to the running config and compiles the commands needed to apply the archive to the running-config. It then executes them and the configuration the takes immediate effect.