Operating systems affected: MicrosoftTM Windows XP, Windows Vista, Windows 7
To clear dns cache:
ipconfig /flushdns
To restart dnscache service:
net stop dnscache
net start dnscache
You can also do this visually from MMC. Just type services.msc in run/search and use appropriate command in order to restart dnscache service.
Benefits: could solve web browsing problems if internet connection is ok with many websites but not with all.
Also it is good to see if you recently moved your hosting and you have changed the name-servers.
This apply just for desktop computer you use to browse when everybody see a website but not you. For DNS servers, it is another story.
Also it is possible to clean DNS cache per browser like Firefox, etc. like you can see on other articles on this website.