Backup when not booting up

[Lesj]

My Macbook needs to have OS taken off then installed again. Its not booting up. When swithed on it only goes to a white page with a circle and diagonal line - no further. Apple say take off and re-install OS. I need to back up on Time Capsule first.
How do I do this if I cannot boot up the Macbook?

I do not bwish to lose the info on it so some help would be really appreciated.
Thanks.

 

[Spawn_Dooley]

You can asking your Apple Store to do it. There will be some cost there to be expected, or you can try FireWire Target Disc Mode ... you need another compatible mac and a FireWire cable ... read more about it here.