Okay, now we know that at least your integrated graphics will work. The trick is to narrow down what might be wrong with your external graphics card.
You might try removing the card completely, then re-inserting it, just to make sure it wasn't slightly loose. Make sure you insert into a PCI-express 2.0 x16 slot. This is an older card that does not appear to have a requirement to plug in a power cable to it, but you might want to verify just to be sure.
Then, reboot your computer and before Windows starts, go into your BIOS and change the settings to use your external graphics versus the integrated graphics.
Your external HD 4550 card should hopefully work now, but your display may look funky as Windows probably loaded basic video drivers at this point.
Finally, if all is still going well, go to the following website to find and install the latest drivers for your ATI Radeon 4550 videocard: