Zeinyeh,
There is not enough information from you to help yet.
What version of archicad are you using?
What are your computer specifications?
What error messages are you getting (screen shots?)
What size project are you doing?
Please click on your Profile and add your version of archicad and operating system and specs so that this information is always included in your questions.
Erika
Architect, Consultant
MacBook Pro Retina, 15-inch Yosemite 2.8 GHz Intel Core i7 16 GB 1600 MHz DDR3
Mac OSX 10.11.1
AC5-18
Onuma System
"Implementing Successful Building Information Modeling"