I have a Sandisk all-in-one USB 3.0 card reader. It worked with Windows 7.
Since I upgraded to Windows 8 Professional it is not possible to read any CF card; with a card in the slot the LED flashes continuously. I have tried more than one card. The SDHC card slot works OK. I haven't tried the other slots. I have tried a different USB port on the PC.
I have upgraded the bios on my Asus M5A99X EVO motherboard and updated the chipset drivers to the latest version.
The device manager shows all four slots under 'disk drives' and 'portable devices'. The File Explorer also shows all four slots.
Any ideas? Please.