A fastening tool having an alignment device that prevents the tool from firing unless the tool is properly aligned with respect to the object to be fastened. The tool includes a housing and a driver mounted in the housing and moveable with respect to the housing, the driver having a driving surface for engaging a fastener such as a staple. A magazine assembly and nosepiece are associated with the housing for positioning and aligning the fastener in the path of the driver so that when actuated, the driver strikes the fastener and forcibly ejects it from the magazine into the substrate on which the object to be fastened is to be secured. The magazine can be removably secured to the housing. A nose piece assembly having a semi-circular bottom cut-out is secured to the housing and includes structure for ensuring that the object to be fastened is properly aligned in the cut-out before the driver can be actuated. In another embodiment of the present invention, the fastening tool is designed to optionally automatically cause a second object, such as insulated material, a washer, or a gasket, to be simultaneously driven from the magazine with the fastener and secured thereby on the substrate, thereby insulating the fastener, for example, from the item being fastened.