Depending on your existing settings, various problems may occur when using Wi-Fi.
Login window does not appear or the connection cannot be established
- Check if Wi-Fi is deactivated...
- ...on your laptop.
Many laptops have a button that must be pressed before the Wi-Fi connection is active. Other laptops have slider switches to activate the Wi-Fi connection. You may also need to press a special key combination to activate your Wi-Fi connection. Look for a key on a keyboard which has a symbol for the wireless network, which usually has to be pressed with the Fn key. Usually there is a LED on the laptop indicating whether the Wi-Fi is activated.
- ... in Windows Mobility Centre
In Windows Vista and Windows 7, you can activate and deactivate Wi-Fi in Windows Mobility Centre. Enter the first few letters of the word "Mobility Centre" in the search box of the Start menu to access the settings.
- ... by disabling the network connection
The Wireless network connection can be deactivated completely under Windows. Open the "Network and Sharing Center" (by typing the first few letters in the search box in the Start menu) and click on "Manage network connections", or "Change adapter settings".
- ... in the advanced settings of the network adapter
In Device Manager – depending on the Wi-Fi adapter – you can partially disable the transmit function of the Wi-Fi adapter, for example, with options such as "Wireless Off" or “Radio off" or by choosing an unsuitable Wi-Fi mode (examples: 802.11-n only or 802.11-a only). These settings are configured by default and only need to be changed if you have modified these settings in the past.
- Check the date settings on your computer
If the date setting on your computer is significantly incorrect (for example the date is set to the wrong year), it may be that the connection cannot be established, because it is assumed that the validity period of the certificate (required for secure communication with the login server) has expired. Double-click on the time shown on the task bar (bottom right) to check the date and time settings and correct them if necessary.
- Root certificate is not yet active
In Windows 7, the root certificate from Windows may not have been activated yet on brand new computers, as this is done only when it is needed for the first time. To ensure that the necessary certificate is active, open Internet Explorer (!) and connect to an encrypted website at the University of Cologne, for example, the webmail system. If you do not have any other Internet access available, you can also briefly connect via the unencrypted Wi-Fi network and then remove it again. After opening the Wi-Fi login page in Internet Explorer, the root certificate is activated.
- Restart the computer
Under certain circumstances, Windows does not ask for the Wi-Fi login details. Often this can be solved by rebooting your computer.
- Move to another location
Especially within the University Library, sometimes a stable Wi-Fi connection is not available. If possible, try moving to another location. The Wi-Fi signal is stronger when you are closer to the access points.
An exclamation mark on a yellow background is displayed permanently next to the wireless connection.
- Check if DHCP (Dynamic Host Configuration Protocol) is enabled.
If you have set up a static IP address for use in a home network, the connection to the university network will no longer work, because IP addresses are assigned dynamically on the university network. Open the properties of the Wireless Network Connection and set that both the IP and DNS server addresses are obtained automatically in the TCP/IP properties (Windows Vista/7: TCP/IPv4). You can access the wireless connection settings in Windows Vista/7/8 by opening the "Network and Sharing Center" (by typing the first few letters in the search box in the Start menu) and then right clicking and choosing "Manage network connections" from the context menu.
- Wi-Fi signal is too weak
If the Wi-Fi signal is too weak (which can also happen even when Windows displays three bars of signal strength) sometimes the IP address cannot be obtained via DHCP. In this case, you can only try to restart the computer, move to a different location and restart the computer once you have changed location again (please do not use standby or hibernation while changing location).
The connection is established but data cannot be transferred
- Delete any network bridges if present.
Open the "Network and Sharing Center" (by typing the first few letters in the search box in the Start menu) and click on "Manage network connections”.
- Disable Internet Connection Sharing
Try to disable the service for Internet Connection Sharing. You can disable this service in the "Control Panel" under "System and Maintenance", “Management”, and then “Services”. Under Services, select Internet Connection Sharing, disable this service and then restart Windows).
Data transfer is extremely slow or websites load slowly
- Move to another location
All computers connected to an access point share the available bandwidth which is also limited by the Wi-Fi transfer rate. If many people are connected to an access point and are transferring data simultaneously, the connection will be slower for everyone. The connection will also be slow if you are on the edge of the Wi-Fi coverage area where the signal is weaker. If possible, move to another location where fewer people are accessing Wi-Fi or move closer to the access point.
Map of access points
After some time, the connection is interrupted and data is no longer transferred
- If you are using a laptop on battery power and you have particularly restrictive energy saving settings in Windows Vista, the Wi-Fi connection may be interrupted after some time, even if the signal strength is good. To prevent this, open the "Power Options" (type it in the Start menu) and edit the settings for the “Power saving mode". Select "Advanced Settings". Under "Wireless Adapter Settings” select "Medium power saving mode” rather than the maximum.
- Move to another location
If the problem is not caused by the power saving settings above, you will unfortunately need to move to another location with better signal strength. Updating the driver or firmware for your Wi-Fi adapter may improve the Wi-Fi performance.
If you are still unable to connect to the Wi-Fi network and you have followed the troubleshooting options above (or you are having trouble understanding the instructions provided) bring your laptop to the RRZK-Helpdesk. We recommend calling us first to avoid lengthy waiting periods.
If you have any questions or problems, please contact the RRZK-Helpdesk