Windows 7: Cannot type & some programs say 'another user'

My keyboard types fine in some programs and browsers but not others. I tried different keyboards with same results. I cannot type anything in the Opera Browser & Microsoft Word now refuses typing. In Opera sometimes typing is accepted but then in a flash form (Crossword on USA Today site) the keyboard letters record as numbers counting the keystrokes. I tried the on-screen keyboard with same results.

Also on occasion, software will not open and shows an error message 'Another User is using this software'. But I am the only user. After 'sleep', my Logitech Camera does not reactivate and says another program is using the device. Could these issues be related to the keyboard problem?

I suspect a setting is wrongly set in the operating system. But don't know what. Anyone else have these problems and what is the remedy?



Been fighting this issue for 5 weeks.
Using Windows 7 Professional 64 bit on AMD processor with 16GB memory.

Fixed this problem. It was a security software called GuardedID. It intercepted my keystrokes and changed the signal. I disabled the software and all is now working. Hope this can help others.