No, probably not. This fake alert most likely has to do with the streamviewer exe that you downloaded and ran.

We've been monitoring a FakeAv/Koobface/spyware delivery scheme, and today the group dropped their standard FakeAv moneymaker and added a set of phony codec gimmickry to their back of tricks, redirecting the user's browser to v-s-codecpro.com/purchase.php?code=, all while popping scareware messages about corrupt sound and video codecs. See the prompt in the lower right hand corner here:



The codecs on your system are most likely not corrupted, they were not corrupted on our infected lab system.

Source: http://blog.threatfire.com/2009/06/warning-media-system-on-your-computer.html