There are almost 100 variations on the R4 cards - so many manufacturers and different models.
You MUST use the correct firmware for your particular card or you will most likely be stuck on the "Loading" screen.

Your box should indicate the website to use - go there , download and setup your card according to their instructions.
If you don't have the box anymore then you will be stuck with trying all the different firmwares you can find to get the right one.

Once you get your card working - make a backup on your pc , cd or hdd.
then you have a base point to start from when something goes wrong.