From which manufacturer this card is from? XFX, Gigabyte or Asus? Have you tried consulting with the manufacturer's website for product support.
In Device Manager..do you have any yellow marks?
What was the previous graphics? If Nvidia, run DDU and select Nvidia to delete any remaining settings.
Is Win7 fully updated?
** Windows 7 and Windows 8.1 must be fully updated before attempting to install any AMD driver. All 'critical', 'recommended', and 'optional' (no language packs,etc) updates as well as any Service Packs (SP) must be installed before any attempt to install graphics drivers. If you do not get this message .... keep installing until you do: