Follow the below instructions to add DART to the PATH variable in Windows
STEP 1: Go to Desktop, right-click on "This PC" and then click on "Advanced system settings" on the right side.
STEP 2: After that "System Properties" Popup Box will be opened, click on the "Environment Variables" button as shown below
STEP 3: Now select "Path" under "System Variables" and click on the "Edit" button
STEP 4: Now, we will copy the path where we have downloaded the Dart SDK as shown below
STEP 5: After that click on the "New" button and paste the path and then click on the "OK" button as shown below
Now we can use Dart anywhere in the file system
STEP 6: Running Dart using command prompt but with different file system location