There seems to be a myth passed around by students that a W on your transcript will keep you from being admitted to a university. There might be some extreme cases in private or out-of-state universities in which a W negatively impacted a student's admissibility to that university. That could be attributed to the fact that some colleges and universities will indicate a W along with the grade that the student had earned at the time of withdrawal; in other words, if the student was making an F in the class and withdrew from it, the student's transcript indicated WF for the course, meaning that the student was failing at the time of withdrawal.
DVC, however, does not follow this practice. If you withdraw from a course, your transcript will merely indicate W. And, according to UC officers at a recent UC counselors conference, the UC system will disregard a W on an applicant's transcript. Therefore, W's have no impact on your transfer GPA. However, having a great number of W's on your transcript might have a negative impact on your admissibility, as admissions officers might consider a large number of W's as an indication that you do not complete what you begin. If you have extenuating circumstances, such as an illness, a disability, or other reasons for frequent withdrawals from courses, use the "Additional Comments" section of your university applications to explain why you have a large number of W's. Accentuate the positive: Point out that you have overcome your challenges to be successful in other courses, and that you didn't let your circumstances impede your progress toward your academic goal.
One final point to remember: F-1 international students are expected to complete a minimum of 12 semester units each fall and spring in order to stay in legal immigration status. PLEASE talk to an international student advisor in the ISAS office before you withdraw from any courses.