If security sites are blocked then you may have a malware (virus) infection.

Do a malware check with a few malware scan programs.
You need to use all programs because each detects different malware.
Make sure that you update each program to get the latest version of the database before doing a scan.

If you can't download the files on your computer then you need to do that on another computer and transfer the files to your computer via a USB stick or CD-ROM/DVD or try to download them from other sites (e.g. www.filehippo.com).

• http://www.malwarebytes.org/mbam.php - Malwarebytes' Anti-Malware
• http://www.superantispyware.com/ - SuperAntispyware
• http://www.safer-networking.org/en/index.html - Spybot Search & Destroy
• http://www.lavasoft.com/products/ad_aware_free.php - Ad-Aware Free
• http://www.microsoft.com/windows/products/winfamily/defender/default.mspx - Windows Defender: Home Page

See also "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked and What to do when searches take you to the wrong search website

not able to load that sites too:(

Then do a malware/virus check with your current anti-malware software.

You can try an online scanner.

• http://vms.drweb.com/online/?lng=en - Dr.Web - innovation IT-security solutions.
• http://www.eset.com/onlinescan/ - Free ESET Online Antivirus Scanner
• http://www.kaspersky.com/kos/eng/partner/default/pages/default/check.html?n=1246229256418 - Kaspersky Online Scanner 7.0

You can download thew recommended programs using a different PC and save them to a USB stick. Then transfer those programs to the infected PC via the USB stick.

Well, I'm on a Mac, have no malware, did the "safe mode" thing, did a clean install, & it's still buggy, CPU usage bouncing around from about 120% all the way "down" to about 70%. Sometimes it says it can't even find GOOGLE's server!!! Something is really wack about this, I get "Unresponsive Script" messages, when I've not even done a thing, and no window or tab is opening; then click on cancel, and still nothing happens, heck, when I tried to shut it down to do the re-install, it wouldn't even close without it being forced close.... I've about had it with this memory-consuming, slow-moving, buggy browser...