I loaded a backup and when I reboot I get only the dots ... I can't boot ... I have installed the multiboot and I can access the terminal via the recovery mode ... How I can load a backup for the terminal?

PD: i can't flash... my usb can't connect with pc... only charge

Depends on what type of backup you're talking about.

If it's a .tar or .tar.gz you can simply untar it..

no... i can access to osso-backup folder and here are applications folder pre-backup.d post-backup.d and resotore.d files... can restored wih this files? because the home folder is empty.... all this using recovery mode from bootmenu

can't run maemo only see the 5 dots...

Sorry but you're not providing enough information.

What exactly have you done?

You say you "loaded a backup". HOW? You also say you installed multiboot. HOW and WHEN? (i.e. before or after "loading the backup").

Plus, if you're N900 can charge then it can also connect to a PC. Which OS are you using?

Plus, the folders you mentioned above (pre-backup.d, etc.) are just the settings for the osso-backup program, which are useless for restoring, especially if you are not using the osso-backup program to restore the backup.