I changed drivers the other day, I erased all my ati drivers etc, but did not restart pc. so when I went into (display, settings etc.) and went to adaptor it showed no drivers. When installing ati drivers etc., you have to have some kind of driver there, I got same error. So I restarted pc and let windows put a standard driver in for me. Then when i went to install ati drivers etc. it worked because it was able to recognize a driver and replace it.
See if that works also.
always before putting in new hardware, erase existing drivers to avoid complications...