I recently bought a Dell Inspiron 15, operating on Windows 7. Everything had been running fine until the other day, when Windows Live Messenger would not sign in, I couldn't log into Facebook or into Windows Live Email. I think it is due to me not being able to access secure sites. It seems I have tried everything to fix this. So far these have not worked:

-Changing Internet Explorer 8 Settings, adding these sites to my Trusted sites, enable SSL, clearing caches, deleting temporary files, Cookies, Browsing History, AutoComplete.

-Downloading Mozilla Firefox - this does still not load the pages.

-I have Norton Internet Security 2010, I tried uninstalling this and I still couldn't log in.

-Turning off every firewall or protection for the internet.

-DNS flush-ing

-Downloading Malwarebytes Anti Malware, running a scan and fixing the issues that arose.

-System Restored, but upon restarting it told me System Restore did not work

-In the Run window, tried the following:
regsvr32 softpub.dll
regsvr32 wintrust.dll
regsvr32 initpki.dll
regsvr32 dssenh.dll
regsvr32 rsaenh.dll
regsvr32 gpkcsp.dll
regsvr32 sccbase.dll
regsvr32 slbcsp.dll
regsvr32 cryptdlg.dll
some were successful, others did not work.


Just to clarify, I can get onto the home page of all the sites but when I sign in it comes up with 'Internet Explorer cannot display the webpage', Mozilla comes up with a similar error message.

I don't know what else to try, any advice would be greatly appreciated.
Thanks