Unsafe connection

[samqweqwe]

hello,
I have recently upgraded the cpu fan on my computer and also added in my old graphics card (now two graphics cards but different series(radeon hd 7850 and radeon hd 5450). i put it back in as i could not store it in other places. Any way, I then turned on my computer and clicked firefox and it loaded up with a page that says :

This Connection is Untrusted

You have asked Firefox to connect securely to www.google.co.uk, but we can't confirm that your connection is secure.

Normally, when you try to connect securely, sites will present trusted identification to prove that you are going to the right place. However, this site's identity can't be verified.

What Should I Do?

If you usually connect to this site without problems, this error could mean that someone is trying to impersonate the site, and you shouldn't continue.


I then restarted my computer to see if that would help but then i noticed an error with dropbox saying that it cannot connect to a secure connection. this is the same with windows update. some programs still work like google chrome, ie and crysis 2 (online).

does anyone know how to fix this problem?

thanks in advance

EDIT:
I have tried wired and wireless connection
i have the edimax EW-7728In if that helps

 

[samqweqwe]

I fixed the problem

for some reason the time and date was changed but i put it back to normal time and its fixed

 

[RealBeast]

That is the most common cause of the problem, you may need a new bios battery. If your computer date and time are not within the authorized range of time of the security certificate you will get that warning.