HELP, cannot access secure sites

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

It is, still nothing.

1. Click Start, and then click Run.

2. In the Open box, type one of the following commands, and then click OK (copy and paste is your best friend):

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

4. Click OK when you receive the message that says DllRegisterServer in FileName succeeded.

5. Repeat for each command line listed above