The updates to NV2 are a large (~75 Mb) exe file that you ‘run’ to install the new version.
Assuming you have downloaded it and can see it on either your dektop or in an explorer, you just Double-Click on the file. This will bring up the installation dialogs where you specify where to install NV2.
To go back a bit – all updates to NV2, whether they be service-packs or whole new versions, are complete installations of NV2. They are installed exactly the same as if you were installing NV2 for the 1st time. All you need to know is where your present version is installed so you can install the update in the same place. If you are unsure about this, then run the old version and click on Help , then About.
Close to the top of the resulting help page you will see something like:
Just intstall the new version in the same directory path as you see next to ‘Directory’ and you will be fine.