You probably won't like this suggestion, but I found my USB760 works much better with a CradlePoint MBR1000 router than it does plugged into my laptop and using the VZAccess software. I'm using Windows XP, so it works both ways, but much better with the router.
First, go to a system restore point before you even got VZAccess manager on Windows . (will erase VZAccess Manager and other programs installed after VZAccess manager). It is somewhere in Control Panel, in Systems and Maintenence.
Then, go to www.vzam.com and find the compatible software by going to Consumer Download and selecting your device and OS.
Finally, download and install the software.
If that doesn't work, do a system restore again, use GlaryUtilities or Advanced SystemCare (google it) to remove any invalid registry issues and other problems with your computer.
If it installs but still doesn't connect, you need to activate your device by going to Options>Activation. If that doesn't work, got to Options>Detect Device or Options>Run Wizard.
If that STILL doesn't work, post the issue and I will get back to you.
this is a brand new windows 7 laptop without any history of use. it's plain vanilla windows 7 purchased a couple days ago. all firewalls, security etc. have been disabled to see what the issue is. i'm waiting on a call back from the level 3 engineers. case was put in yesterday for them to call me back. please help if you can b/c i've spent at least 8 hours trying to troubeshoot with and without verizon support.