To open a DfW database, just download, unzip to a folder and then doubleclick on the .DFW file to open it.
YOU MAY GET AN ERROR MESSAGE WHEN YOU DOUBLE CLICK ON A DFW FILE. BECAUSE OF A BUG IN WINDOWS, THE WINDOWS FILE EXPLORER KEEPS THE FILE OPEN AND PREVENTS DARTS FOR WINDOWS TO OPEN THE FILE. IF YOU GET AN ERROR MESSAGE, CLOSE DARTS FOR WINDOWS AND THEN OPEN DFW AGAIN THE NORMAL WAY. THE DATABASE YOU TRIED TO OPEN IS SET AS DEFAULT WHEN YOU DOUBLE CLICK ON THE DB SO IT WILL OPEN ON THE SECOND ATTEMPT
You could also of course unzip the .dfw file to a folder of your choice and then open it from the "File" menu in DfW.
Below is a more in-depht description on how to download a dabases and view its contents.

Darts for Windows is used a lot in national and international tournaments. I often get databases a from my customer and contacts in the darts community. I always share my databases with the users of Darts for Windows by uploading them here on my site (www.dartsforwindows.com). Darts for Windows can open any database created with DfW, so in this article I will try to explain how you can download one of my databases and view all scores and stats from the downloaded database.

Ok, we start by downloading the database from Ladbrokes.com WDC 2008. Click on the link Ladbrokes.com WDC 2008 under the section "download dfw databases" on the right side of the frontpage.

When you click on the link, a message dialog box will pop up and ask you what to do with the file. Click on the "Save" button to save the the database file (in compressed zip format) to a folder of your choice on the hard drive. It's very important that you place the file in a folder you know how to access after the download is finished.

In my sample I choose to save the database to the Darts for Windows database folder. If you have a normal installation of Darts for Windows, you will find the database folder in
C:\DartsforWindows\database

Click the save button and wait for the download to complete.

When the download is done, browse to the folder where you saved the zip file and unzip the database file. Windows XP and up has support for zip files buildt-in in the operating system. I prefer to use Winzip (www.winzip.com). If you don't know how to unzip the file, search Google for help or use Windows' help system.

In this sample I use Winzip. All I have to do is highlight the file by clicking on it once and then right click (right mousebutton) the file. From the popup menu I click on "Winzip" and then from the sub menu, I click on "Extract to here".

The extracted file is named "Ladbrokes2008.dfw"

The database file is now extracted and ready to use.
Start Darts for Windows.
Click on the "File" menu in the upper left corner and then click on the menu item "Open" or press CTRL-O on the keyboard.

Browse to the folder where you unzipped (decompressed) the database file and then click the file "Ladbrokes2008.dfw" and then click the "Open" button.

A warning message will appear after clicking the "Open" button in the dialog box.

After a couple of seconds (depends on the speed of your computer) the following message dialog box will pop up:

Click "OK" and the database is ready to be explored.

To view averages, legs, scores, outshots and so on, click the "View" menu and then on any menu item of your choice.
To view all the scores from one of the matches in the newly loaded database, click on this link for a howto on how to view scores and stats from a previous match.