is there a driver software that would allow me to control motors only directly from computer

Am using pronterface, but for this you need to connect the thermistors otherwise you get error 0. I want to test my printer before I have to go through the full connections. Does anybody know a driver software which will allow me to do so. i.e. control the motors diretly from the computer. Am using Megatronics V2.0 board by the way.

Why you don't want to connect the thermistors? You don't have them? Why you want to get something else that does what your board already does?
I can't understand the question here, but thermistor = resistor. If you read the specs of a standard thermistor they said 100k, so if you don't have a thermistor to connect to your board, just go to radio shack and get a potentiometer 100k and fake your thermistor (do not connect your heater cartridge nor heater bed).

Or, reconfigure the firmware so that mintemp is below the bottom of the thermistor table. Just be sure to put it back before you run the printer for real.

just solder a 100k resistor to a socket and insert that in the thermistor pins. remove it when u are done.