Gezando, there was a thread a while back where you asked about people having problems with the Windows XP service pack 2. That has been quite a bit in the news lately. The main problem seems to be with the automatic firewall that comes with the service pack. It "protects" you from hackers so vigorously that it protects you from yourself, too. In particular, it won't let you go to some web sites, such as banks and credit card sites, etc., to check on your accounts. The recommended fix is simply to uninstall the firewall and put in an independent one instead.
Although I don't have XP, I have encountered the same problems. Every time I download a new "security patch" from Microsoft, I find that there is something else that I can't do any more. For instance, now I cannot submit my grades to the university from my home computer.
I accidentally found a backdoor solution, if your computer won't let you go to a particular web site. Go to another computer (any computer still running Windows 98 will do, for instance), go to the site on that computer, then email the url to yourself. For some reason the web site will open from the email link, even though it won't open directly from Internet Explorer (!?)
So you can pass that tip on to your friend, if he/she is still having that problem.