I'm writing to tell you about how we students use computersin our daily lives．为什么要去掉 about呢?

I'm writing to tell you about how we students use computers
in our daily lives．
为什么要去掉 about呢?

tell somebody something
后面的宾语从句how we students use computers 修饰something

about去掉 没有的，我写给你就是要告诉你，比如美国人很少用we students，一般直接用students

因为：tell sb sth . how引导的从句是宾语从句。tell 要接双宾语。