Notes about the DET file extension:
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 DET file type is primarily associated with 'ACT!' by Best Software CRM Division. Sometimes associated with .UNQ saved unknown attachment. Windows ver 6, 5, 4, 3. Popular contact management software.