If you computer automatically play a voices like" congratulation ,you are qualified to get the special promotion ......"and constantly pop up a window explorer even you are not using the IE browser,your computer is infected by a virus ,you might accidentally download a virus or a spy program to your PC.
try go to the C:\WINDOWS find for the file name :Vsaqua.exe and delete it.If you can delete the file ,try use the program such as "the unlocker "to delete it.
You can get this free software at http://www.emptyloop.com/unlocker/