Insert a microSD card into your computer that you will be using in your Raspberry Pi;
Make sure there is no data on the microSD card, or make sure that you backup any data you would like to keep. The microSD card will be wiped during the installation of the MainsailOS.
Open the Raspberry Pi Imagerprogram;
Main Menu
Select Choose OS;
Choose OS
Select Other specific-purpose OS;
Other specific-purpose OS
Select 3D printing;
3D printing
Select Mainsail OS;
Mainsail OS
Select Mainsail OS v.0.6.1;
Mainsail OS v0.6.1
Please note that the Mainsail OS version may not be the same as it is updated frequently. Choose the version that is available to you in the Raspberry Pi Imager (you will update the versions of Klipper, Moonraker and Mainsail in later steps).
Select Choose Storage;
Choose Storage
Select your USB Mass Storage Device USB Device, make sure it is the SD card you inserted above;
USB Mass Storage Device USB Device
Select Write;
Write
A message will appear 'All existing data on 'USB Mass Storage Device USB Device' will be erased. Are you sure you want to continue?';
Select Yes;
All existing data...
Wait for the write and verify to complete (100%);
Writing...
Verifying...
If installation completes successfully you should get this message, 'Mainsail OS v0.6.1 has been written to USB Mass Storage Device USB Device. You can now remove the SD card from the reader';
Select Continue;
Write Successful
Close the Raspberry Pi Imager program;
Remove the microSD card from your computer;
The Raspberry Pi Imager should have 'ejected' your microSD card automatically from the Windows OS.