Issue with browsers and certificates

[MasterZuFu]

I'm having an issue with my browsers. I have three:

IE
Firefox
Opera

Only IE is using certificates correctly, the other two are either flat out denying all certificates or telling me that they are untrusted or they don't know who the issuer is. I can't connect to any https sites with firefox or opera, and alot of times IE just does this:

Connecting
Connected
Connecting
Connected
Connecting
Connected

Error: Could not connect to site


So I'm pretty much just sitting here, unable to sign in to half the sites I visit. I have no idea what's going on, but it's really starting to piss me off.