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 Z02 file type is primarily associated with 'WinRAR' by RARLAB.
Z02 is usually the third compressed file in a series, preceded by Z01.
The Z Archive System is a set of programs used to compress, extract and view files and folders on Unix-based systems. It is self-extracting meaning data can be extracted by executing the folder itself.
WinRAR for Windows is able to uncompress Z Archive files.