You could try adding an entry to your Windows' host file. This will explicitly tell which IP address to load when requesting a hostname, rather than requesting it through DNS, which you may be having problems with.
You may have trouble obtaining the IP address of the websites in question, as you usually do this by pinging their host name, and if you have a DNS problem, then ping won't be able to find the end destination. You could ping the hosts from your friend's machines, you could probably find an online ping service, or you could post the list of host names here, and we will return the IP addresses.
Once you have the IPs, open the file C:\Windows\System32\drivers\etc\hosts. Add one entry per line in the format:
Save the file without an extension, and reboot.
Another solution may be to run a tracert command from DOS. If DNS is failing, you may be able to see at what point it fails. You could then provide the results to your ISP - they may be the cause of the DNS failure. You can save the results of the trace route by using the command:
tracert xxx.xxx.xxx.xxx > c:\results.txt
A third solution could be that you need to flush your local DNS cache. Open CMD and run the command:
You can also use the command
to view the DNS resolver cache.
Also, some questions:
- What anti-virus & firewall software do you have on each computer?
- Do you have any browser security plugins?