Adware:Adware (or spyware) is a small program that is designed to show advertisements (in various form and degrees of intrusiveness) on your computer. It often reports personal information back to its owners. As a result your sense of privacy can be violated.
Search-Explorer is an Internet Explorer toolbar that provides specialized search functions. It may redirect your search requests to its controlling server and may also monitor and record your Internet activity, gathering information that may be personally identifiable. Search-Explorer may also install new applications onto your computer, at any time, with or without your knowledge or interaction.
Technical details (How to remove SearchExplorer(pop up))