My home network mostly consists of Macs and backup is done using Time Machine to a NAS drive (QNAP). Time machine backup works flawlessly, however I have two laptops running Windows 7 which I would like to backup to the Qnap as well. One of them uses the Professional edition, which is fine (but slow!), the other one uses the Home Premium edition, which does not seem to have support for networked backup.
I understand that all versions of Win7 supports the Windows Home Server for backups. Is there any open source server that emulates such a beast (much like the QNAP flawlessly emulates the Time Capsule)?
If that fails, is there any other way to backup the Win7 home machine over the network (without reinstalling Windows)?