I just downloaded a couple of files that are .rmvb. I have Windows Media Player and Quick Time. Neither of these players, however, will open the file. If someone could tell me how I can view these files and a program to convert them to WMP or Quick Time that would be great. Thanks
Download Real Alternative. You can either use the player that it want’s to install (its a good one) or you can install without a player and use WMP. 
This is a Real Media variable bitrate file. So nominally, you need RealPlayer to view it, or better, use RealAlternative as DS suggests. (RealPlayer is a pretty clumsy and invasive thing.)
As for converting it to something else, well, no. It’s possible, but you need a bit more experience with conversions and more understanding of what you’re doing. You can try the free Super convert from eRightSoft, but it may well fail or give you awful results. You’d need to get into VirtualDub and some custom scripting to really do much.
I wouldn’t waste time converting something from the real format. I don’t even now why people still use it.
Thanks for the replies guys. RealAlternative worked great and I just won’t bother converting.