Hello Celin, Thank for assistance and advice. I tried all possible drivers but the problem remains. It seems there is a conflict between IRQ of the network (H10) and the one specified by VFP500. Moreover, not all but there is only a few computers (desktop)in our office that experience this problem. If we connect the computer with a local printer, it's OK. The same machine, when connected with a network printer, it went off ! (All our printers are HP). Thank in advance.