Ce este un DNS? Un DNS (Domain Name System) reprezinta un sistem prin care se translateaza un nume de domeniu si nu numai (ex: www.sasnet.eu) intr-o adresa IP (ex: 123.456.789.10). Necesitatea operatiei de translatie este datorata faptului ca Internetul functioneaza pe baza de adrese IP, domeniile fiind folosite la memorarea mai usoara a adreselor de Internet de catre utilizatori. Cu alte cuvinte, un DNS este un server care converteste un URL intr-o adresa IP si invers. Exemplu: Aveti un server de cs,aveti ip-ul 123.456.789.10 ca sa nu mai trebuiasca sa il tineti minte, va puteti conecta si la DNS adica CS.SASNET.EU ! Cei care au probleme in recunoasterea DNS-ului sunt din 2 motive: 
1) Windowsul nu are setarile necesare sau intre timp s-au pierdut 
2) Providerul dumnevoastra de internet(firma) are blocat DNS-ul pe anumite site-uri(caz rar) 
Rezolvare:
 
Example: Changing DNS server settings on Microsoft Windows 7
  1. Go the Control Panel.
  2. Click Network and Internet, then Network and Sharing Center, and click Change adapter settings.
  3. Select the connection for which you want to configure Google Public DNS. For example:
    • To change the settings for an Ethernet connection, right-clickLocal Area Connection, and click Properties.
    • To change the settings for a wireless connection, right-clickWireless Network Connection, and click Properties.
    If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
  4. Select the Networking tab. Under This connection uses the following items, click Internet Protocol Version 4 (TCP/IPv4), and then click Properties.
  5. Click Advanced and select the DNS tab. If there are any DNS server IP addresses listed there, write them down for future reference, and remove them from this window.
  6. Click OK.
  7. Select Use the following DNS server addresses. If there are any IP addresses listed in the Preferred DNS server or Alternate DNS server, write them down for future reference.
  8. Replace those addresses with the IP addresses of the Google DNS servers: 8.8.8.8 and 8.8.4.4.
  9. Restart the connection you selected in step 3.
  10. Test that your setup is working correctly; see Testing your new settings below.
  11. Repeat the procedure for additional network connections you want to change.