We have two computers in the house, they share the same modem (ADSL). Used the internet as usual, then we went out for a few hours, and when we came back we couldn’t access, google, gmail, yahoo mail, hotmail. Can get into all other pages, that we try. We can make skype calls to other skype users, but not paid for skype calls to land lines. Have you experienced anything similar? Or do you have any idea what it could be?
Viruses and spyware can cause various problems such as pop-ups and not being to able to connect to a web site. You can get malware from web sites and email messages. When you use the Internet you should have an up-to-date operating system, firewall, virus scanner and a spyware scanner and make backup copies of your important files regularly. If you have Windows, you should start it in Safe Mode and then scan for malware using your virus scanner (if you have one) and then with various spyware scanners as one spyware scanner can’t find all the spyware. There are a lot of web pages with instructions on how to remove malware and fix your computer:
http://www.google.com/support/bin/answer.py?answer=502&topic=8995
http://security.yahoo.com/
http://www.spywareinfo.com/~merijn/programs.php
http://spywarewarrior.com/index.php
Another option is that your web browser’s cache is full, so try emptying it:
http://www.google.com/support/bin/answer.py?answer=497&topic=8995
Also, check the settings of your firewall so that it doesn’t forbid HTTP access (web sites).