I do have several computers in my office, and unfortunately, the network admin has yet to patch my cables (which I'm not allowed to). So far, I'm stuck with Wifi, so I configured one of my Windows 8 computers with ICS on the Wifi-module and route the rest of the computers through that one.
However, Windows seems to drop the wifi-connection and therefore kill internet access on two occasions: if I lock the computer and if the computer is inactive for some time.
For the first problem (wifi drop on locking the screen), I have not found any information whatsoever.
All I found so far are hints on the power settings, where the wifi can be deactivated if the computer progresses into power saving mode - I did change that without effect on the problem. According to some websites, this problem is quite known, but I haven't found a solution yet.