Can't access https sites - Vista 64-bit Home Edition

[flaco]

I recently purchased a pc for my son. It came preloaded with Vista 64-bit Home Edition. We can pretty much get to any site we want on the Internet, but when it comes to https portions of the sites, the browser chugs away for a minute or so then I get an error indicating that it can't get to the page.

I have seen tons of posts and sites talking about the same problem, along with several things to try to get it to work. Everything from turning off firewalls, to adding the sites to the trusted sites, to netsh commands. My head is spinning trying to figure out what the silver bullet is that will get this to work.

Can anyone out there tell me how to get this working. Just some more info. We have McAfee Security Center as well. I've tried many combinations of turning things off in both Vista and McAfee. I figure with all of the cases of this out there, someone will have to have an answer.

Thanks in advance.