If it's green then you definitely have it, though it may be in another name.
Right-click the column headers in Search. Library and Downloads and enable the
SHA1 column. Now you can see which one is turning green.

Delete the ones that try to download software. They are spam.

When you search and before you try to download anything, right-click it and
get a Bitzi Ticket. Most of the spam and trojans have been found and identified there.