There are many applications to record screen activity. Some free, some not. Most commercial one will allow you to download a trial version (although probably limited in some way (e.g. maximum recordable time, or a banner).
The two most famous (probably) are the free CamStudio and the commercial Camtasia. Note that on the CamStudio page there is a Google link to the commercial product. The links for the free CamStudio are about 2/3 of the way down the page. Even Microsoft has a free offering - Expression Encoder (although it's not too clear if the free version captures screen activity).
Insanity is hereditary, you get it from your children
There is a slight problem in that all Google images have copyright on them, but supposing you can get around this, what about dissolving from one image to another? It's not the same as a zoom of course, but the effect is quite pleasing.
The best program I've found is Camtasia -- however, there are a number of things to consider in order to get a good quality video.
Here are my recommendations, from a thread at Premiere Elements support site Muvipix.com.