I imported GIFT format files. The quiz now has a navigation bar with a slider and counter at the top left corner of the screen. How do i remove it?

That is because you do a preview that is not in Browser, only available for SWF output. That control panel is easy during editing because you see the slide number and can easily stop immediately going to edit a specific slide using the pencil icon. This has nothing to do with importing a GIFT-file at all, may I change your title, please? Another tip: do not put the question in a title/subject,  it is not meant for that. You have a section for a title (which is misleading in this example) and then you have the section to explain the issue.