DSL Embedded :: Running DSL on Windows without a trace

Also, you can sometimes "fix" the problem by doing this:

Move your mouse pointer over the qemu window and then click on it so that you are back "inside" your qemu virtual machine.

Then slowly press and release individually each key that was used in your last keystroke that caused you to exit qemu.

For example, if you left qemu with ALT-TAB, then

Press ALT
Holt ALT
Release ALT

Then

Press TAB
Hold TAB
Release TAB

Same is also true for other escape sequences like CTRL-ALT-DEL etc

original here.