I need help with error message!

I just switched from dial-up to DSL 2 days ago. The installer could not get me connected to the internet and the tech on the phone said I needed a new NIC card. After she left, I called my son, who is good with computers, and after playing around with it we were able to connect it to the internet (the password was entered wrong in the setup). I now can browse the web, but I cannot access any secure login sites (my bank, my credit cards, my Ebay, my state site, etc.). I receive an Internal Server Error 500 on every secure login page; I can't even access my own account on my new DSL company home page! I am running Windows XP. We turned off the firewall, then turned it back on, we uninstalled IPV6, we rebuilt the HTTPS .dll files in the registry, we uninstalled Norton Internet Security (I've since loaded AVG), we reset the firewall settings and the winsock. I called Tech support and the insisted it must be a problem with my internet setup and to call Microsoft (I was running IE7 at the time). I uninstalled IE7 and went back to IE6. Then we installed Firefox 2.0.0.11 browser. I did not have this problem on dialup, so I think it must be in their router or their system. Am I wrong? Is their anything else I should try? I wrote the company a long email, hoping to get another tech that may be more willing to help, but I feel I've been left out in left field. I don't know if you need anymore info about my system, but I'm willing to give it if you need it. The router is a Siemens Gigaset SE567 and my computer is an HP model V194H. Thank you for any help you can offer!

 

http://support.microsoft.com/kb/311766/en-us
http://support.microsoft.com/kb/294849/en-us
http://support.microsoft.com/kb/832981/en-us
Maybe something in one of these links will help. Some of the info is pretty techincal, and there's lots of network jargon (especially in the first link) so maybe have your son take a look if you don't quite understand some of it....

Happy Holidays

....and Welcome to MajorGeeks! :major

 

Thanks for trying! I think we finally have it figured out - something was clicked that shouldn't have been and we are OK now! So simple, but so hard to find! Thanks!