the 1720 error is a pretty generic MSI Installer
error, it could be caused by many things. If you have an actual MSI
file, you can generate a log file with this syntax:
C:\>msiexec /i <filename.msi> /l*vx somename.log
This will create a text log file called somename.log (or any other name
you want to use). Inspect it using Notepad. It will give more detailed
information about what, exactly, is failing.
However, this only works if you have an MSI file. As I recall, the Cisco
VPN Client comes wrapped up in an EXE file, so you can't easily pass
command-line parameters to the MSI. If you can extract teh MSI from the
EXE wrapper, then you can run it from msiexec, with logging turned on.
