With a 56kbps modem (guess you mean dial-up) connection, you can expect around 6-7 KB/s download speed. Grandpa wrote a good guide for maximising LW's performance with a dial-up connection, have a look & see what you think
http://www.gnutellaforums.com/showpo...33&postcount=5

VLC won't preview from within LW for Windows users. You'll have to open your incomplete folder outside of LW & preview from there. Go to your library, click on Incomplete Files then Explore... the folder will open for you! Go from there.
You might have to change what files WMP associates with (it can be a stubborn thing), to make VLC your default player. In WMP go tools > options > file types. Untick all formats that you don't want WMP to play > apply > ok.

The same rule of opening a folder applies to launching completed videos with VLC... have to open the saved folder outside of LW.