You must install the latest VISA drivers to solve this problem. MAX 2.0 needs the NI-VISA driver in order to access the COM ports on your system. Without NI-VISA installed you will be unable to access or create serial, GPIB-VXI, or TCP/IP interfaces. Please check out the link below to download the latest NI-VISA drivers.
http://digital.ni.com/softlib.nsf/webbyproduct?openform&product=NI-VISA
Ryan Tamblin
Applications Engineer
National Instruments