PC is switched off. Switch on your PC.
The Media Manager software is not running. Start the Media Manager software.
No wireless network adapter connected or range too long (weak radio signal). Connect the wireless network adapter to your PC or re-position your Wireless adapter. You may check the link quality by pressing the MENU button and selecting Network > Wireless Info > Signal Level.
Network host (PC) or wireless base station is switched off. Make sure your home network is operational before you try to contact a networked computer with the Streamium.
Your Wireless Base Station/network router employs MAC filtering and prevents the Streamium from connecting to your network. Add the Streamium MAC address to the list of devices that may connect to your Base Station/Gateway router (see its user manual for how to do this). Press the MENU button and select: Network > Wireless Info > NIC MAC Address to see the wireless MAC address.
Not enough USB bandwidth available for a wireless USB adapter. If you share the USB bandwidth with other heavy USB bandwidth users (like USB cameras, scanners or re-writable drives, etc.), the remaining bandwidth may not be enough.
Radio interference from other (wireless) devices. Check whether a wireless connection can be established with other devices switched off. (e.g. microwave ovens, other wireless devices, etc.)
(Wireless) network problems. See advanced network problem solving on page 51-52 of the extended User Manual on CD-ROM.