Thank you All for your response. I finally solve the problem after many attempts. I tried to reinstall the DNN platform again and there was nothing new rather than the error about not enough space for database processes keep appearing. However, this time I didn't give up, I click the "Retry" button for several of times and the magic happened, the installing progress bar passed over 15% and overcome the error.
I don't know what exactly happened. I guess that because I use shared hosting service that means the data space is shared with other ones as well, so when someone else release some space and I suddenly have enough memory for installing process then the problem is solved .

Cheers,
Tim