With the arrival of RISC OS 5.28 you are probably thinking about updating an existing machine. This has become a lot easier with recent RISC OS releases.

With previous updates I have backed up my data and create a new RISC OS setup. This is no longer necessary, as you can now upgrade your system, retaining all your current settings.

So I am going to update my RaspberryPi 3 (which is running 5.27).
 
BACKUP your critical data
There is always a risk that the installation could cause errors. So BACKUP any thing which is important to you first.

Update the Disc contents
1. Download the HardDisc4.zip file onto your RISC OS machine.
2. Open the file and run the Obey file InSituBootUpdate. I ran this directly from the zip with no issues.

The installer will backup the files in !Boot

3. Copy the contents for Apps, Diversions, Documents, Printing, Utilities into your copies to replace everything with new RISC OS 5.28 versions.

 
Upgrade RISC OS ROM
1. Download the RISC OS 5.28 stable ROM (you do not need the complete SD card image just the ROM) from the Download page. As I am using a Pi, the correct file is this one

2. Copy the new files into PCLoader

3. Reboot

Rebooting
1. When you first reboot, you will get a black screen with a command line prompt and a scary error message about SWI &42701 Not Known
2. Type in RMReinit Squash
3. Press return
4. Reboot
5. You should now be running RISC OS 5.28. Check in the RISC OS info window.
 
I did need to reinstall CloudFS due to a known issue (which Elesar were very helpful as usual with) and then I was happily running as before.
 
Final thoughts
I upgraded the Operating Systems on both my Pi and my (Intel) Mac last weekend. The Mac installation was slicker and more automated but took a lot longer to download and install. Next time round I will update my copy of RPCEmu to 5.28
 
Useful links
There is a very helpful guide on upgrading and a really useful discussion forum thread here.