Download Drivers/Software EW3250:
Mac OS drivers:
EW3250 MAC OSX drivers (upto version 15.6)
Unzip the downloaded Windows drivers file, in Windows:
It is important that after downloading, the zip file is extracted.
Once the zip file is opened, then the text "Extract All" is present in the top right corner of the explorer, click on it and launch "setup.exe" (application), from the extracted folder.
Start the "setup.exe" by right clicking on it and choosing "Run as administrator".
Other possibility is, to create your own folder on the desktop, select all the files from the zip file and drag everything to the self-made folder.