The -70 error is usually a General Disk access error Reading file. So normally i would check the Hard drive on the Server or maybe the network card. But seeing as how you said you have other machines that are fine I would start by first making sure that on those 4 machines that those users of the PC have Administrator rights or equivalent. Make sure they have full rights to the ISTS folder on those workstations so they can both read and right to the folder. As well as make sure they have rights to read and write to the DBAMFG or EVO folder. My guess is that is where the issue is going to be.