@shah

You do not have to unmark (remove the flag) from a question. There is no penalty for having a question marked. However, it is better to remove it, because marking/flagging means "I still have to re-check this question".

Sir is it important to remove flag after attempting a previously flagged question

KS,

If you left behind and didn't answer some 100 question, then I would not expect to pass the exam.

From a person who has taken a few professional certification exams in the past: When you mark a question to go back to it, make sure that you answer. Even a guess has a 25% chance of being correct. Never leave a question unanswered.

My strategy is that if I flag or mark a question, I put in my best answer and then come back to it, just in case time runs out and I don't get a chance to review.

Harry

same thing happend with me...my exam was well and i left behind more then 100 flag and fail the exam

Ok. Thanks Simon. The mistake I made was that I didn't review any question. I didn't review the flagged questions either. When next I rewrite it, I think I will just review all questions, at least to be on safe side. What do you think?

You determine which questions you wish to flag.
On actual exam, after you flag a question, you will have a screen after Q240, it will ask you if you want to end the exam, review all questions or review flagged questions.
Normally, you flag questions that you are unsure of, or take too much time, remember no more than 2 mins.
The purpose of it, is to save your time and organize yourself. It will be affect any other things in Exam, definitely not score.
For myself, I reviewed all question during first part of exam. I find it too tiring, so I only reviewed flagged questions for second part.
It is same concept for your email when you flagged an email.