Hi Darrell,
I am running Windows Vista Ultimate x64. I encountered this same error and I
was installing cisco vpn client 3.5.1 as it was the version I had.
Unfortunately I did not check if this version was compatible. However since I
did this my entire computer is next to useless.
The Cisco vpn client began the install which then failed (but marked as
completed).
When I tried to use any internet based application it fails to load
page/communicate (firefox, IE, skype, pidgin, putty, etc)
upon exiting the program I get a hard crash (asking to debug or close).
I then tried uninstalling the client and it failed to uninstall.
All internet based applications still fail however there are a couple
things that still work which indicates there is some sort of driver that some
applications ignore. here is the list of working applicaitons:
telnet (can go to port 80 & get a page)
windows update - my computer is still updating
Firefox Minefield x64 beta build 1 (but not build 9 - latest).
I have tried manually uninstalling/deleting any registry keys or drivers as
per the follwoing url's recommendations however half the files didn't exist
and the problem was not resolved in any way.
http://www.cisco.com/warp/public/471/vpn3K_uninstall.html
http://forums.microsoft.com/TechNet/ShowPost.aspx?PostID=2077694&SiteID=17
I believe it attempted to install a driver at one of the OSI layers (most
likely a SSL driver of some sort from my understanding of how the client
works) however since the install failed there was no driver file and now it
is stuck in some state where anything that uses this driver crashes.
Please let me know if there is any other suggestions. At this point my only
option appears to be to reinstall windows which seems overkill. I also tried
using the follwoing versions of cisco client however I cannot begin the
install I was hoping they would cleanup the mess made by the 3.5.1 installer.
Cisco VPN Client 5.0.00.0090 BETA
vpnclient-win-msi-5.0.01.0600-k9.exe
vpnclient-win-msi-5.0.00.0340-k9.exe