We have a snail like broadband connection but YouTube is normally OK up to 480p definition. It is however no good at 720p, reasonably enough given BT's pathetic local link. So there may be some mileage in the advice to clean up your disk and defrag it.

Downloading & converting isn't a bad idea either, and most of the free software apps which do this also allow you to change coding formats, write to DVD etc.

As for RealPlayer, I can't stand its intrusiveness. In particular I'm fed up with its endless exhortations to upgrade and its attempts to become one's default player. Why would I want to buy their product when they act like hackers?