Re: I can't get into the community groups.

Hi, I found some resources for you:

http://answers.microsoft.com/en-us/ie/forum/ie8-windows_xp/content-was-blocked-because-it-was-not-signed-by-a/bfab51b2-a027-42fc-a829-72dfbe06d7af

http://www.ehowstuff.com/how-to-fix-content-was-blocked-because-it-was-not-signed-by-a-valid-security-certificate-on-internet-explorer/

(On this page there's a method mentioned where you need to perform some changes in regedit, if you're not familiar with this application, please, do not try the second solution, try only the first one.)