After in installation of Update for Windows 7 for x64-based Systems (KB2661254) or Update for Windows XP (KB2661254) some secured web sites cannot be accessed.
The technical detail are that Internet Explorer will not allow access to a website that is secured by using an RSA certificate that has a key length of less than 1024 bits.For more details see: Microsoft Security Advisory: Update for minimum certificate key length and Microsoft Security Advisory (2661254) .
When accessing a secure website - using https://hostname - with an untrusted security certificate, Microsoft Internet Explorer (MSIE) will display a web page that claims that "There us a problem with this website's security certificate." and gives two options. The second option is "Continue to this website (not recommended)." If the second option is selected (by clicking on it) all that happens is the webpage saying "There us a problem with this website's security certificate." is redisplayed. No matter how many times you click on "Continue to this website (not recommended)." the page will be redisplayed. You will not be able to get to the secure website unless you change to another browser (e.g. Google Chrome).
Why this occurs
After installing the Update for Windows for KB2661254 MSIE prohibits access to secure websites that have a good level of encryption but that do not have a great level of encryption.
Remove Windows Update for KB2661254
This requires using the control panel to restore Windows to before the update was applied and then applying all updates except the one for KB2661254.
Use another Browser
Google Chrome and Firefox are not affected by the Windows Update for KB2661254. Therefore, you can use either of these browsers in place of MSIE.
Update the SSL certificate for the website
If you are the webmaster for the secure website or can contact the webmaster, then the SSL certificate needs to be replaced by one with at least 1024 bits for the encryption key.