If you are unable to access Google, we suspect that clearing your
computer's host file should solve the problem.
To access your computer's host file in Windows, open the Notepad program.
Click on File, then Open. You will see a new window asking which file to
open. Make sure the drop down menu labeled "Files of type" at the bottom
of the window is set to "All Files" instead "Text Documents."
For Windows XP, Window NT, and Windows 2000, go to
C:\Windows\System32\Drivers\etc\hosts.
For Windows 98, Second Edition and Windows Me, go to C:\Windows\hosts.
Once you have opened this file, remove any line containing google or
www.google.com and save the file.
If this process does not resolve the situation, it is likely that the
Qhosts-1 Trojan program is installed on your computer. The Qhosts-1 Trojan
program is a virus that creates and embeds a fake host file on your
computer. The Trojan program may have been installed on your system
automatically without your knowledge when you downloaded an otherwise
harmless piece of software, such as a peer-to-peer networking program.
Alternately, you may have been tricked into clicking on a disguised
download button while visiting a website. It is also possible that a
pop-up downloaded this program onto your computer.
You can read more about Qhosts-1 at:
http://vil.nai.com/vil/content/v_100719.htm
http://sarc.com/avcenter/venc/data/trojan.qhosts.html