Howdy!
The file path has changed for World of Warcraft 8.1. Going forward, only the different files between installations will need to be downloaded. As an example, if you install a PTR client it will only require a small amount of disk space on top of your Retail install, instead of the full installation of the PTR that it takes currently.
Old filepath: C:\ProgramFiles(x86)\WorldofWarcraft
New filepath: C:\ProgramFiles(x86)\WorldofWarcraft_retail_
As for the error: Unable to start up 3D accelerator, means the game is having an issue interacting with your video card.
Try running the game in DirectX12:
- In the Blizzard Desktop Application, click Options and select Game settings.
- Find World of warcraft
- Check " Additionl command line arguments"
- In the box type “-d3d12” with out the quotes
If the issue continues copy and paste your Dxdiag into your reply. Hightlight the text and select the code block icon </>.
Thank you!