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.
WinTaskAd is a typical adware application that shows undesirable pop-up advertisements. It can secretly get into the computer from some malicious web sites. WinTaskAd drops its files into the default computer directory and alters the registry, so the threat could run on every OS startup.
Technical details (How to remove WinTaskAd(pop up))