When I try to do anything involved with security e.g.purchase something using a credit card,use my Frequent Flyer password number,etc. I get the message "This page cannot be displayed". Also,when I try to perform a "Windows Update", I get the message,"Windows Update Error".

Sounds like this is an SSL connection. It's only used for encrypted connections. Do these few steps: Click START / RUN / type in: "regsvr32 softpub.dll" (w/o the " 's) then, START / RUN type in: "regsvr32 wintrust.dll" (no quotes) Then try to access the site again If you're still having issues, try these next steps, and after each step, go back to an SSL (https://) site, and see if you can browse. Check the date / time on your computer (mainly the year) correct if necessary Go to Internet Options via Control Panel then Content / Clear SSL State and go to Advanced / Restore Defaults If you're still having problems as this point, try repairing IE, to do this: Go to control panel / add remove programs / Microsoft Internet Explorer / Click "Change/Remove" / select the 'Repair' option If you don't have Microsoft Internet Explorer listed in Add /remove, it doesn't have a repair option, or you've already tried this and it failed, try downloading IE6SP1 from http://microsoft.com/ie and running a new installation.