I have a schengen visa from czech republic,and i wanna enter the schengen area from vienna,will it be ok to do so?,and if i did so will they consider it a bad history when i apply for schengen again?
If you entered to schengen zone with current visa second time, the entering schengen zone from other country will be absolutely ok.
If you entering schengen zone for a first time with current visa, you should pretend to spend most of the time of your travelling in czech republic. However it doesn't matter from which country you will enter the schengen zone. The only problem can be with the migration officer - he can ask you to prove your staying in czech republic. In this case you should have a travel tickets (air/train/bus) and prove of accommodation (hotel booking/letter form friend in czech republic/etc.)