I just downloaded and notice that the installation documentation says the following:
Installing Real-time NetFlow Analyzer
Operating System One of the following 32-bit operating systems is required:
* Windows 2003 SP1 and later
* Windows XP SP2 or later
* Windows Vista Business and Ultimate Editions (IPv4 mode only)
Will NTA work with Windows 7 64 bit?
Windows 7 can be used for evaluation only; not as a production server.