http://community.visual-basic.it/Luc.../06/20617.aspx
Your maximum size for System Restore may be way too large, you should adjust this. By default Vista sets the maximum size allocated for VSS (VolumeShadow Storage) to 15% of the disk size. With some of newer drives, this can result in a huge amount of space being allocated and used.
First, free up all of your disk space by deleting all but the most current
restore point. Go to Start/All Programs/Accessories/Disk Cleanup and you
will see the option there.
Go to Start and type cmd.exe in the results, right click the cmd.exe
item and select the "Run as administrator" option. OK the UAC prompt.
When the command window opens, type the following.
vssadmin list shadowstorage
Press ENTER.
The result will show the current amount of Used, Allocated, and Maximum
allowed size for the Volume Shadow Storage on your system.
The following command will set the maximum amount of disk space used for
the shadow storage to 2GB.
vssadmin Resize ShadowStorage /For=C: /On=C: /MaxSize=2.0GB
Press ENTER.
(type the command as shown, including the spaces)
You should see a message that the command succeeded.
This command assumes that your system drive is C:
Perņ io ho disabilitato il system restore subito, visto che uso acronis true image.