Extra characters added while typing
On any field that needs input, extra characters are added (eg Seeeeeeeeeeeeeetmmmmmefffffffvtttttehhhhhhh ... when trying to type Steve). hitting shift will stop the additions which restart on the next keystroke. Also sometimes get a green edged screen , with an orange box in bottom right with a keyboard icon and a box showing contents of field and an 'encrypting' message. Have tried restart and reinstall .... and scanned with Sophos no problem. This was happening on other programmes as well, but now only Firefox is effected. Did have the latest Windows 10 update recently. Any suggestions gratefully received. Thanks.
Alla svar (1)
It was in other applications? Now just Firefox?
Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox.
A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?
Start your Computer in safe mode. Then start Firefox. Try Safe websites. Is the problem still there?
http://encyclopedia2.thefreedictionary.com/Linux+Safe+Mode Starting Any Computer In Safe Mode; Free Online Encyclopedia
Open the computer's settings and look for the 'repeat key' option.