Wifi for the DSi

So I researched on how to get Wifi for my DS without using a wireless router. They made an official Nintendo transmitter which I havnt been able to find, so I bought another unofficial one off ebay. However, it required me to set up an AD Hoc system to turn it into a proper wifi transmitter. It doesnt have an officaial brand name on it and just says 802.11b/g 54Mbps wireless USB adapter. Problem is that the DS or the Wii won’t pick up on it and I can’t seem to figure out why. The seller is no help at all and just says look it up on youtube. The PC says that its working fine, so has anyone done this before or knows how to?