Try making an Acronis Bootable Rescue Media to a small USB Flash drive and boot from it. You will need to access you Boot menu at start up of the netbook. There should be a message about the boot menu or BIOS Setup when you switch on the netbook.
On my Advent 4211 Netbook I could only make a suitable bootable USB Flash Drive if it was about 128MB or smaller or formatted to about 128MB or smaller, but this problem may have been peculiar to my netbook.
Plug in the USB Flash Drive and your back up media before booting to ensure that it is recognised and available for use during backup.