How to record user actions on workstations (eg record a VNC stream from a station)?

Question

Software testing

Tell me, dear, maybe someone solved a similar problem: we are
analyzing the actions of users of the new program. The simplest thing is to record what is happening on the screen, and then analyze it.
There was a problem of recording user actions on a remote machine. You have to write for a long time: there is a desire to look at the change in the behavior of users over time (from fatigue, from the flow of information on the screen) during the working day, i.e. time limit ~8-10 hours).
The option to use VNC is fine, but accurate video recording is difficult. Let's say there is a program pyvnc2swf, it writes to swf files (the format does not really matter, you can view it), but sometimes it has a habit of writing everything as it should, and sometimes it stops for 10 minutes, and without any errors, just stop adding data to files.
The OS on the machine dedicated for recording is Windows 7, I can take * nix, but both there and there vnc2swf is the same, and there is no other sensible software that catches my eye.
Who got out how? Putting the camera behind the user's shoulder is not an option, this is not a test lab, normal working conditions, people will be uncomfortable. Alternatively, you can write in pieces (albeit for 10 minutes), but somehow automatically start recording the next piece after the completion of the previous one - I did not find an option for such automation.
Thanks in advance for your advice!

Answer 1

Any decent keylogger can take screenshots on mouse clicks/keystrokes. The result is almost a video, but very compact. Maybe this option will work.

Answer 2

Tried with keyloggers - doesn't work. In fact, you have to sit and click constantly on "take a picture."
We have several users, they all work, we need to automatically record their actions, and then we study offline.