Guest Additions Error installing

[Tere]

hello,
ver 4.2.4 I can not install the "Guest Additions" in windows 7 home premium 64.
attached the log.

other Q.
2) is there a software to backup VirtualBox machine? eg as VMbackup for Vmware?

3) with a 40 GB VHD file I saved already 80 GB of snapshots, the SSD is fast but small, 240 GB. can I set the folder of VirtualBox vms on another internal SATA HD?

thanks for your help.