Help me now plz! How to block a virus site from automatically accessing the pc?

Try restoring your computer to a point before you clicked on the virus. Go to System Restore, and it'll give you directions from there.

Sorry to tell you but you are already infected. Next time you boot your PC unplug your Ethernet or turn off your wireless. Get a friend to download Malwarebytes and Superantispyware on to a cd. You can also use a USB thumb drive but after you put into your machine I'd consider it infected and don't use it again unless it's formatted with a Linux machine or a Mac.

Anyway, after your friend downloads the .eve for Malwarebytes and Superantispyware put the cd into your computer and try to install them. If you can't install them try right clicking on the .exe and select Rename and rename the installer to anything else you want. Try installing the programs and running the full scans,several times with reboots!

Try turning on your computer and see if it try's to load the malware site, if not update all your malware programs and make sure your Windows install is up to date. There's a good chance the site took advantage of a known security flaw in Windows. After you update try running Microsoft's own Malicious Software Removal tool by going into Run type CMD>in the command line type MRT and follow the prompts to run the tool. In Vista or Windows 7 you can just type MRT in the start search box to get it.

The other choice is to back up your data then do a full format and reinstall then your computer will be clean and fast again, again the key is to make sure Windows is up to date.

You know I did not turned it on for 2 days. And when I did it today. my AVG antivirus detected and deleted don't even know How?