1) You can download a wireless Ethernet adapter driver all day, but if you Do Not have a wireless adapter card installed in your computer, the drivers do you no good.
Or if you do not have a wireless USB adapter plugged into a USB port.
Example of a wireless adapter card,http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=4695358&CatId=2692
Example of a wireless USB device,http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=6367137&CatId=2692
Example of an Ethernet adapter card, http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=686143&CatId=200
If you are just going to hardwire the computer, just buy an Ethernet adapter card, (PCI version), and install it in your computer, (On the motherboard), in any available white PCI slot.
IF it is the Mini Tower model.
The Desktop, Small Form Factor (SFF), and Ultra Small Form Factor (SFF) computers, are too small in width for a regular size Ethernet adapter card.
They need a Low-Profile Ethernet adapter card,http://www.newegg.com/Product/Product.aspx?Item=N82E16833114034
This is for a Dell Optiplex GX620 Mini-Tower computer,http://support.dell.com/support/edocs/systems/opgx620/en/ug/A02/mtabout0.htm#wp1051997
Scroll the page down until you come to the bold blue heading - System Board Components
This is an illustration of a Top view of the Mini-Tower's motherboard.
16 and 17 point to two PCI slots.
This is where an Ethernet adapter card that is the PCI version, will plug into.
PCI slots are White in color.
An example of a basic PCI slot, ( 3 are shown),http://en.wikipedia.org/wiki/File:PCI_Slots_Digon3.JPG
If you do decide to go wireless;
1) Wireless networking operates at half of the speed of wired networking.
A computer that is wired directly to an Ethernet adapter card, is twice as fast on the internet, as a computer that is connected wireless.
2) Make sure your Router is capable of wireless.
Make sure the wireless router has a built-in Modem, or that you have a separate Modem.
[ For DSL.
Phone line connects to Filter. Filter has a place for a telephone cable, and an Ethernet cable.
Ethernet cable connects to Filter, and other end connects to Modem.
Ethernet cable goes from Modem to Wireless router that does not have a built-in Modem.
Phone line connects to Filter. Ethernet cable from Filter goes directly to wireless router, that has a built-in Modem.
Computer has to have a USB wireless device, or a wireless adapter card, installed.
For additional questions, or to clarify anything I have stated, please post in a Comment.
(Believe upper right of your page, blue Comment)