There are two reasons: first, the software is not downloaded to enter the website as required, and second, the network system is faulty or the network speed is slow, so you need to wait.

A program can open a variety of files, and a file can also have a variety of open programs. You can click the "attachment" link on the webpage, select "Save" in the pop-up dialog box, select a folder on the hard disk, download it to the hard disk, and if there are related programs on the computer, you can open it.

Specific operation: Open my computer, click Tools-Folder option in the drop-down menu, deselect the extension of hidden known file types, and confirm. . Dwg is a file generated by vector drawing software AutoCAD, which is opened by AutoCAD and PhotoShop. The original English name is sensitive vocabulary:. Ddf ddf files are called diamond instruction files and text files. Open in Notepad or any text editor. . Dbf is a database file.