How do I delete every other row in a large spreadsheet?

I have a rather large spreadsheet (~100,000 rows) that represents my music collection. I have imported directory info from about 60 directories/subs into the spreadsheet. Somehow along the way I have duplicate entries from several directories that represent about 4,000 duplicate entries. How do I go about deleting these duplicate entries? I figure a Macro could probably delete every other row - just not sure how do set it up. I just need a method to delete every other row within a given range.

Thanks.

I'm using 2010. Where is the "remove duplicate" feature located? Oh never mind I found it. That seems to do the trick -- thanks!!