On the destination drive runs out of space

Hi,

I have Acronis True Image Home 2010. I can't save a full-backup-image.
I become always a PopUp with the information: "On the destination drive runs out of space "
-> Auf Deutsch: "Auf dem Ziellaufwerk geht der Speicherplatz zu Ende."
I can "Ignore" or "Abort"..

My System:
- Win XP SP3
- Acronis True Image 2010
-> Tasks and Logs -> new Task -> Partition C: and D: --> Full Backup

The image are about 40GB. I can't save on the internal hard disk or on a external USB-Disk.
My free space ist over 300GB.

thx 4 help