blocking Internet homepage

[HELLIAN]

hello since yesterday evening my home page has changed without my intervention, it is blocked on some portal on Mozilla Firefox and I can not restore so can you help me? It is a Vista machine on a laptop and it has just started some time backs.

[.:MUNDITO:.]

Problem: the ISP is blocking these at its DNS server.
Solution: use the Open DNS server

How?
Test whether you are blocked by trying to go to megaupload.com or justin.tv or myp2p.eu - you should see the red "this site be banned" horror screen. (If not, either you are already using a method to get round the block, or else the ban has been lifted)
Connect to your router from your internet browser, by entering its IP address in the panel where you would normally write a www address. You need to check your router's instructions, but it will be close to: 192.168.1.1 (Some routers demand that you are connected to them using a cable instead of wireless).
Enter the username , password. See post #7 if you've forgotten it.
Find the place where the DNS addresses are displayed. Copy them in case you need to go back later. Then overwrite them with:
208.67.222.222
208.67.220.220
Save and exit.
You should be able to go to the blocked sites from ANY PC connected to your router.

More info: google search for open dns. Should be first in the results.

Caution: don't use this method if you feel that you can't trust Open DNS. All of your data will be routed via their servers and so it is technically possible for them to read any information that is not encrypted. Normally your bank login activity and session normally is encrypted end to end, but some forums and websites might not be. Check if your browser is showing the privacy symbol before entering any credit card info on line (but you do that anyway, don't you! ;-)

[Zachary]

Can you post a hijackthis log here: HijackThis - How to use HijackThis? What it dose?

[Big Fish]

Check on the immunization page

Think Prevention:

Put in place a good hosts file
http://www.mvps.org/winhelp2002/hosts.htm

How To Download and Extract the HOSTS file:
http://www.mvps.org/winhelp2002/hosts2.htm

Repeat that proccess about once or twice a month