CERN has a large Windows 95/NT infrastructure with more than 3500 PCs connected that is used as one of the main information services for the laboratory. This infrastructure is used for a wide set of services, including Office Automation, Computing Aided Engineering, Calculations, Software Development, and ... controls. This paper will describe the CERN generic infrastructure for Windows 95 and Windows NT and then give several examples of PC control applications and future directions. The implementation of an object oriented device server based on Windows NT and ActiveX in the CERN ISOLDE-REX experiment will be reported