Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries, unused processes and other unfavourable system settings to identify slowdown issues.
The ETE file type is primarily associated with 'EpsilonTest' by EpsilonSoft.
[Italian Link] Epsilon Test is a software package aimed at drafting, administration and evaluation of tests to answer on a school LAN (local area network).
The software is targeted at teachers who wish to play fast exercises, having a simple and flexible instrument for their immediate assessment.