Partial KB failure on reboot

On two Logitech wireless kb’s connected either by USb or PS-2 directly to the computer, small case w, f, e stop responding. Caps work for them with either shift key but not caps lock. Placement of receiver seems to have no effect. This occurs on alltyped input-mail, video reply, etc.
(The fact these letters are now working probably due to fact I am asking for help!!)
Both KB’s have fresh batteries, no damage due to fluids or impact. OS is XP Home with SP1 and all critical updates; problem started suddenly with no new installation of software or hardware.