This page gives you a few things to try if you find yourself stuck.
This can happen for several reasons. A few exaples:
*Status
command to display the CMOS RAM settings.How to fix it depends on what the problem was.
*LoadCMOS
command to load a known-good CMOS settings file. If you have a Raspberry Pi, see CMOS RAM on the Raspberry Pi.What may happen is that the RISC OS logo appears during the boot, but instead of the desktop you get an error message.
boot_delay
parameter in config.txt – see config.txt (Raspberry Pi). It may also indicate that you have additional disc drives connected (see next bullet point).It is possible for an application (usually a game) to change the screen resolution such that when you return to the desktop the icon bar isn’t visible at all, so you can’t get to Display Manager to change the screen resolution to something more sensible.
The easy fix is to press CTRL-BREAK to reboot, but you may not want to do that (e.g. you have unsaved work). In that case, proceed as follows:
wimpmode 32
1 You probably won’t see a command prompt, but you might notice the desktop display shift upwards slightly.
This will typically happen if you’ve somehow managed to select a RISC OS monitor type that is unsuitable for your monitor.
wimpmode 32
(as mentioned above).If nothing happens when you press keys on the keyboard and/or click a mouse button (but the mouse pointer still moves) this may indicate that an application is misbehaving. Try each of the following in turn:
2 If you successfully use ALT-BREAK to quit the application, the system could still be unstable. Save as much work as you can, then shut down and restart.