dd-wrt restoring from backup configuration

One day my WRT54GL is running slow and afterward it become strange, strange and hang!!! great, and I couldn't even access it. After awhile play with it, I use everybody's formula that is RESET it then become default configuration. fortunately, I keep the backup configuration 3 months ago on my laptop.
How to restore it?. See the followings show:

1. Go to Administration>Backup to see this page
2. Click Browse on Restore settings to take the backup file from your local laptop
3. Point the file, in my case the file name is 13-decWRT54GL.bin, and click open button from the dialog window. Once you're back on dd-wrt control panel, click save button next to backup button at the bottom.
4. Wait for the restoration process because it takes sometimes to finish Then you will get the last known working configuration.

Easy..