I always had bad reception with the ICS, even being 3 feet (1m) away from my router. I think the antenna is bad design. Also it seemed to connect better with different router. Had a hard time with the Cisco router from my ISP, but worked better with a TP-Link for some reason.
Also check your system event log, on my I had disk error especially when downloading big file which slowed down or hang the download altogether. It felt the internet was slow but actually was something else
We ultimately returned a ICS bought for a conference room TV at the company I work for because the WiFi was so poor. The stick was plugged into a HDMI extension bank in a cabinet under the TV. We have a Cisco WAP321 at the other end of the room on a table. Despite reporting full signal strength it was impossible to operate remote desktop or even internet browsing because it was so slow.
Very disappointing given that the stick itself is a brilliant concept in itself but reading some reviews WiFi is a bit of a letdown with this product. We decided to exercise our return rights rather than work on it because we felt it was potentially a weakness in the product rather than our environment.
Hope you can get it working if you decide to stick with it (pun intended). Keep updating the BIOS, Windows and the Wifi & Bluetooth drivers. You might get some success.