I am searching for a tool that allows background recording of my pc screen. I it is nothing like a spy tool, I just need to be able to check what I was doing at the some time in the past. Small impact on the system, and relatively small size of recordings, as it is supposed to run all time pc is turned on. Some recording management as auto pruning of recordings older than x days.

UPD This is not a problem if some scripting is necessary to achieve what is described in the question. So it could be a command line recording tool which could be used from batch, bash (cygwin, mingw) scripts.