My bank, RBS, encouraged me to download and install "Trusteer Rapport" for extra security, from within their secure site.
Internet worked normally until after I'd logged off.
Thereafter I was unable to logon, much bafflement, the only change was this bank recommended "security" program.
Accessing the 'net via other computer and putting "Trusteer Rapport problems" into search engine brought up the usual masses of other users complaining of similar difficulties.
Uninstalled T R and normal service resumed post the usual cleanup of T R traces.
FWIW?