In a first test setup the harddrives were hooked up with SATA cables to two laptops, one running Ubuntu 10.4, a second one with Windows. If the HD booted and data was still accessible, an image was copied to a seperate harddrive. The seperate harddrive have a folder structure according to the HD number. We tried out several free software programs to restore harddrives and access data: Testdisk (Linux), Photorec (Linux, PC), PC Inspector (PC), Recuva (PC).
On this way, the content of 4 harddrives could be instantly accessed and copied.