?
Strange that some sites work and some don't.
I'd try flushing the DNS cache on your machine and see if that makes a difference.
Go to the command prompt by clicking on:
Start
then
Run ( type in
cmd)
This will bring up the command prompt window...that is the old style DOS looking window. Then type in this command:
ipconfig /flushdns
Make sure to leave a space between the word
ipconfig and the
/flushdns
It's a bit of a long shot but it won't damage your system in any way and it will remove old DNS entries and force your system to query the DNS server every time you go to an internet address, so the first time you connect to a site may take a bit longer but after that thing should be normal...if it works.
Good luck and don't throw the computer out the window...unless I'm just outside!