You should have direct 3d already, the hardware on that netbok is probably not good enough to run what you are trying to. You can try to download and install a new video driver from Acer support for your model. Lesson here is, don't get a netbook and use it for games, netbooks are very basic email/document/web browsing machines.
From the game site:
Video Card: 128MB**
**Supported Chipsets - Nvidia FX 5900 Ultra or greater; ATI Radeon 9800 or greater; Intel 82915G/82910GL or greater.Earlier cards may only display 2D Match Viewer Mode and are not supported. Earlier cards may require the DirectX 9.0 SDK is installed to run the game. This can be downloaded from the following url:http://www.microsoft.com/downloads/details.aspx?familyid=5493F76A-6D37-478D-BA17-28B1CCA4865A&displaylang=enLaptop
versions of these chipsets may work but are not supported.