That sounds a lot like the problem i had not long ago after the client crashed. Reinstalling didnt help for me because there were probably some stored settings hidden somewhere in a registry jungle..
But after reinstalling the client a new shortcut appeared in the client folder that started eve in safe mode(not premium graphics and windowed mode). After starting it up like this i could exit and start eve normally and then i just had to turn on premium again and everything was back to normal.
If you managed to come back in with classic client you will probably get premium working as soon as that is installed tho.