Ok as you pointed out the drivers only want to install in a vista or earlier version. So here is how I got it to work with Ver. 6.9.
1. Go to Vzam.net and pick out the 6.9 ver. for the SMT5800 after the verification page for your cell number you should be at
VZAccess Manager
2. If you haven’t already download the VXAccess manager as well as #2 the drivers. (yes I know they are included but I believe they need to be separate for the next task)
3. After both are done downloading right click on them for "Troubleshoot Compatibility"
4. Choose Troubleshoot Program
5. Click on both "The Program worked on earlier versions" and even though it may not be required "The Program required Additional Permissions"
6. Choose Vista Service Pack 2 for both
7. Install the drivers first
8. Then VZAccess Manager. Stop before you do the Recognize Phone Option
9. Plug Your Phone in and it will go through a driver install with a success message
10. Now let it look for the Phone on a com port.
These directions are a little convoluted but it works for mine. You may figure out a better short cut.