FLV Thumbnails On Windows XP?

Until earlier today, I DID have thumbnails for my .flv videos. Right before I LOST the thumbnails, I had uninstalled 3 programs: DVD Fab, SUPER converter, and VLC Player. Please someone tell me how to get the thumbnails back. And please don't tell me to download a huge codec pack, b/c I already have all the codecs I need. I need to know exactly what component generates the thumbnails, and how to retrieve or enable it.