There are two HD 55xx series GPU card AMD has drivers for: HD5550 & HD5570.
Both use the same two last drivers from AMD which doesn't support your GPU card anymore with new drivers from here: https://www.amd.com/en/support/graphics/amd-radeon-hd/ati-radeon-hd-5000-series/ati-radeon-hd-5550
You have a choice :
1- WHQL 2015
2-BETA -2016
Unless your HD 55xx GPU card is a OEM GPU Card. Then you would need to go to the OEM Support site to get your AMD Driver. The AMD Driver above may work though.
If you don't know the exact Make & Model of your GPU card, download GPU-Z and run it. It will tell you all the data on your GPU card including the Make & Model.
