Can not type the letters T, C, or H in Word

[Rmac]

I hit some unknown key or combination of keys in word and I
can not longer type the the letters T, C, or H

 

[Klaus Linke]

I hit some unknown key or combination of keys in word

and I can not longer type the the letters T, C, or H

You may have hit the Windows Logo key. There is a known problem with MS
Windows NT Workstation 4.0 and Alternative User Input:
http://support.microsoft.com/?kbid=321794

(Thanks to Bo Mings [msft] for pointing out the article)

Greetings,
Klaus