Ok then we know now the System files are good so we move on to the next step.
Windows Vista / Windows 7 Flush DNS
Flushing DNS on newer versions of Windows is almost as easy as the earlier versions but due to Microsofts security additions you must run the command prompt with administrator privileges.
- Click the start button and navigate to the command prompt (Start > All Programs > Accessories > Command Prompt)
- Make sure that you right click on the command prompt application and choose "Run as Administrator"
- Type in the command "ipconfig /flushdns"
Note: It is also possible to type in "cmd" into the Windows Vista / Windows 7 start menu search field and then right click on the cmd.exe result instead of having to navigate through the various sub menus.