I was able to install the driver and VZ Access Manager on Windows 7 64 bit, no problem.
I tried to install it on Windows Server 2008 R2 64 bit on the same system (dual boot). The modem driver appears to have installed OK, but when I launch Access Manager, it crashes at the detection phase.
I would bet money that VZ Access Manager is not supported for Server 2008. I can't even get it to work with Windows 7, even though it says it is support.
If you are able to install the driver and see the USB modem in the device manager, as an alternative, you can create a dial up connection using the modem. This is what I had to do in order to use my device on my Windows 7 laptop.