Sorry but I have solved the problem in the meantime. It appears here was an electromagnetic conflict outside the PC between the wireless keyboard and the WIFI connection. I simply disconnected the WIFI antenna and now I can use my keyboard again. This is wonderful!

Thank you anyway for your quick reply.

Best regards,

Chrstine
I can use my keyboard again.

Its not the problem with the keyboard or the mouse
it seems that you need the full system scan..
of if you have wired keyboard and mouse connect them to the computer and check using them with the same browsers ... which will determine where the problem is ?

if the wireless keyboard and mouse are working fine
then need to update the drivers
or there is some problem Hack / Virus scan (not sure) but don't worry it could be a magnetic effect of speakers or monitor
you have to check them out