We use Cisco VPN Software to access the office from home, Starbucks, etc.
There are several threads on the subject on the net (I used this one). There are a couple of workarounds which are mentioned including backing up the ndis.sys file and putting it back after the install but before the reboot. (This didn’t work for me, my laptop still blue screened.)
Another fix was to run the installer in Administration mode (I opened a command prompt using the “Run As Administrator” from the right click) then ran the installer. (This did work for me.)
One annoying thing was when I imported our PCF file the group password wasn’t imported. I had to use a Cisco VPN Client Password Decoder website to get the password from the PCF file to put into the address book. Everything worked fine after that (at least so far).
Hopefully someone else finds this useful.