Hi gbeerten,
It could be upsetting when the SD Card Reader fails to work. I suggest you to download and install the Windows 7 drivers as drivers for Windows 8 is not available. You can download the driver from the following link:
http://dell.to/YbpAQs
Follow the steps provided below to install the driver in Compatibility Mode in Windows 8:
1. Right-click the program's icon (Setup file) and choose “Properties”.
2. When the “Properties” dialog box appears, click the “Compatibility” tab and then click the “Run Compatibility Troubleshooter” button.
3. In the “Compatibility Mode” section, select the “Run This Program in Compatibility Mode For” check box and select the program's desired Windows version (Windows 7) from the drop-down list.
4. Click “OK” and then run the program again.
Please let me know if you need further assistance.