Hi NG; I have 2 dvb-files one for ACAD2000 and one for ACAD2004. I change these on a regular basis to correct error that the users of the application find. I have these 2 files in a 'Development'-folder on the network and the running version in another folder. When a user starts ACAD it will load one of these files depending on ACAD version. When one user has loaded a dvb-file its imposssible to delete but I found out that its possible to overwrite with a new one. I just copy from the 'Development'-folder to the other one. Occasionly it happens that it isnt even possible to overwrite the file. It says that either the source-file or the the target-file is in use. Any ideas why this happens? Isnt it so that a dvb file, when loaded, is read into the memory so that it should be possible to overwrite it. TIA