You can use 7-Zip on any computer, including a computer in a commercial organization. You don't need to register or pay for 7-Zip. 7z - Википедия
To view the contents of SIYM.7z , you will need a file archiver that supports the format. Common options include: SIYM.7z
Based on your request, "SIYM.7z" appears to be a compressed archive file using the format. You can use 7-Zip on any computer, including