Here’s an interesting error:
The above comes up when trying to install Cisco VPN Client 5.0.07.0410 on Windows XP SP3 (so far). I didn’t have this issue on Windows 7 SP1.
To get rid of the error message download Fix.mst file and run the .msi against it:
START /WAIT MSIEXEC.EXE /I vpnclient_setup.msi TRANSFORMS=Fix.mst /QUIET
Quick screenshots showing what has been done in the .mst to fix the issue: