Microsoft Windows 7

1. Click Start
2. Enter cmd in the Search programs and files field
3. Right-click the cmd.exe
4. Click Run as administrator
5. Enter ipconfig /flushdns
6. Press the Enter key. If done correctly you will see the following message: Successfully flushed the DNS Resolver Cache.

Microsoft Windows 8

Method 1

1. Please perform one (1) of the following:
   • Swipe up from the bottom of the Start screen
   • Right-click anywhere on the Start screen
2. Select All apps
3. Locate Windows System
4. Click Command Prompt
5. Enter ipconfig /flushdns
6. Press the Enter key. If done correctly you will see the following message: Successfully flushed the DNS Resolver Cache.

Method 2

1. Right-click the Start box at the lower-left of the screen
2. Click Command Prompt (Admin)
3. Enter ipconfig /flushdns
4. Press the Enter key. If done correctly you will see the following message: Successfully flushed the DNS Resolver Cache.

Microsoft Windows 8.1 / 10

1. Right-click the Start button
2. Click Command Prompt (Admin) or Windows PowerShell (Admin)
3. Enter ipconfig /flushdns
4. Press the Enter key. If done correctly you will see the following message: Successfully flushed the DNS Resolver Cache

Apple Mac OS

1. Click your hard drive icon on your desktop
   Note: By default this is named Macintosh HD
2. Double-click Applications
3. Double-click Utilities
4. Double-click Terminal
5. Enter one of the following depending on version:
   • OS X 10.4.x - lookupd -flushcache
   • OS X 10.6.x - sudo dscacheutil -flushcache
   • OS X 10.7.x - 10.9.x - sudo killall -HUP mDNSResponder
   • OS X 10.10.1 - 10.10.3 - sudo discoveryutil mdnsflushcaches
   • OS X 10.10.4 - sudo killall -HUP mDNSResponder
   • *OS X 10.11.+  - sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder; say DNS cache flushed 
   • macOS 10.12.6 - sudo killall -HUP mDNSResponder; sleep 2; echo macOS DNS Cache Reset
   • mac OS 10.13.6 - sudo killall -HUP mDNSResponder;say DNS cache has been flushed OR sudo killall -HUP mDNSResponder && echo macOS DNS Cache Reset
   • macOS 10.14 - sudo killall -HUP mDNSResponder
   • macOS 10.15 - sudo killall -HUP mDNSResponder; sleep 2;
6. Press the Enter key
7. Enter your administrator password in the Terminal
8. Press the Enter key. You will not see any message. (*Unless OSX V10.11+ the end user will HEAR  “DNS Cache flushed”) The Terminal will progress down to the next line.