For guaranteed safety, check the official IRIS website or contact their customer service via Facebook to request the exact firmware for your model.
An update progress bar should appear. Do not turn off the TV until it finishes and restarts automatically. Download IRIS SAT 42E790S Firmware USB part2 rar
Do you have the (e.g., TP.MS338...) or the Part 1 file already? For guaranteed safety, check the official IRIS website
Using a tool like WinRAR or 7-Zip, right-click on the first part and select "Extract Here." The software will automatically pull data from Part 2 and any subsequent parts to create the single final firmware file (usually an .bin or .img file). For guaranteed safety