Hi, Make sure you enter your username and password in the installer correctly. 
    and make sure the install path is correct 
    1. Download latest installer version 
    2. Load the Dugi installer
    3. Click on the settings and enter your DugiGuides Username and Password (it should say Welcome! Username) if successful otherwise enter your info correctly 
    4. Check install path is correct, try clicking the Auto Detect Path button to fix it
    Win Retail. <your path>World of Wacraft_retail_
    Win Classic. <your path>World of Wacraft_classic_
    Mac Retail. /Applications/World of Wacraft/_retail_/
    Mac Classic. /Applications/World of Wacraft/_classic_/
    5. Check launcher path is correct
    6. Click Reinstall (after a new purchase)