: The most reliable and recommended free tool for this is 7-Zip .
: Right-click only the file ending in .001 , select "7-Zip," and choose "Extract to...". The software will automatically find and join the other parts to reconstruct the original file. Quick Software Review: 7-Zip T4.7z.001
Do you have of the file (e.g., .002, .003) ready for extraction? : The most reliable and recommended free tool
: The design is functional but dated, lacking modern features like a "dark mode". T4.7z.001