Hello!
I just installed iPi recorder on a Windows 7. It recognized both kinects perfectly, i can evaluate and choose the folder to record but as soon as i push start to record the software crashes with a message like " ipi recorder stopped working because of a problem" no more description of what could be the cause of it.
What could be the problem?

Hi
Next update of Recorder will include better unexpected error handling. This will give you a possibility to provide us more details about the error.
For now, you can save a trace log just before pushing the START button. Maybe it will help us to make some assumptions. To get trace log, open the tools menu at top-right and press the SHOW TRACE button.
You may also check if recording starts with other settings. For example - just 1 Kinect, or selecting depth-only video mode, or using other output folder, or other compression method.

Found the problem, the output folder. Thanks anyway.

What was the problem with output folder? No writing permissions?
Anyway, Recorder should deal such situations in a more graceful manner.