It seems the drivers are messed up.
You need to uninstall those drivers, run driver sweeper to clear out any remnants of the old drivers.
http://downloads.guru3d.com/Guru3D--...up)_d1655.html download different set of drivers don't use 185.85 I think they're giving a lot of people problems. Run something like 182.xx drivers. Restart your pc, install the "new" old drivers and restart your PC.
You're memory shouldn't be showing 100mhz even if the card is in 2d mode your memory bandwith is hindering your cards performance and it seems it's because of the drivers.