There are better programs than hypercam:
http://taksi.sourceforge.net/ and
http://camstudio.org/ being two freeware possibilities not to mention many programs have their own output if you want such a thing, fraps is probably still king of the hill though.
To answer your question though you appear to have it on "full frames uncompressed" which is basically a bitmap every frame (and at a meg or so a bitmap for your screen res and 24 of those a second....). You then get to choose a new compressor, if you do not have one installed (and they tend not to be included as much as they did in various codec packs*) you get to install one. I am not sure what standard hypercam2 uses (there are a couple of ones for windows and not all programs support them all) but I would suggest a lossless codec for various reasons (speed and quality being the big two), I am not sure what the state of the art is these days but
http://neuron2.net/www.math.berkeley.edu/benrg/huffyuv.html always did for me (reading around it seems good things are being said about the camtasia one and it should not be tied to the program).
*ffdshow is included in most codec packs primarily as it is great, it does have a compression option though even if later versions of it have been nerfed somewhat. If you do use it you will not configure it hard as it is far more wide ranging than most (most codecs are one type only where this does/did have many).