http://avid.custkb.com/avid/app/selfser ... cId=263545
When I render an animation I use SI's post process movie creation in MOV format using the Avid codec which plays very well on a PC, doesn't take up much space and is a good solid fast codec. A bonus if you have an Avid is that it loads right in for editing.
Just thought I'd mention it as I've found it useful for previewing animation. Much better than what comes with Windows.