Does anyone what you exactly have to do to ensure getting accepted to the ISE department right after freshmen year?
and what are the chances ?
They have a site with admissions percentages for each of the engineering departments. Many of them are very competitive, with 50 percent or fewer being accepted from pre-engineering to an actual engineering degree. Also, that usually happens after sophomore year, not after freshman year.
http://www.engr.washington.edu/curr_students/admissions/admitstats.html