When you run both, you have one character on your desktop but both programs can control it. Hal sits in its box as usual, unless you move the character elsewhere. It does all the things Hal does, but you also have all the features of CyberBuddy as well.
So for example, say you're chatting with Hal. Hal normally doesn't get the weather or news on its own. CyberBuddy does do this. So while talking to Hal, Hal might suddenly give you the news or weather then go back to chatting as usual. It usually works fine, and the MS Agent software that both work off of manages which program can control the character fairly well.
I'm using Windows 2000 Pro, with SP4, 933mhz CPU, 256MB RAM and generally have no problems running both. The only thing I noticed (and this seems to have something to do with the NT platform) is that if I run both together, the HalAsst.exe will not fully terminate. If I shut Hal down that remains running in the background, even though it isn't doing anything. I just go into Taskmanager and manually shut it down, which doesn't seem to cause any problems.
You can run both with two separate characters. In which case Hal does what Hal normally does and CyberBuddy does what it normally does and you now have two characters talking at you. Get enough of these programs and you can have a party on your desktop! (And also use up all your system resources! [

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