We have 5 Win 2003 servers that backup, using Windows backup, to a network drive on an NAS server, also 2003. The files then are backed up from the drive on the NAS to a tape each day. The backup from the NAS folder to the tape is fine and it backs up whatever is there. The problem is the backups going from the other servers to the NAS folder often do not work. The jobs are staggered and are set up as differentials during the week due to time, and run full jobs on the weekends. Each server has its own folder on the NAS drive and the jobs are set to save to that folder and the differentials overwrite each night while the full job for each one only overwrites on the weekend. The jobs often start and the give an error in the log of : "c: is not a valid drive or you do not have access" "Device reported an error on request to write data to media." This usually occurs at the start of the job so I do not think it is a time issue (one job running into another). Some nights they work and other nights they do not, but they are not consistent. Any ideas on how to get them to run each night and not give errors? I have deleted and rescheduled the jobs for tonight on the main server, so I will see how that turns out.