Daret said:
it's certainly strange
Strange is not the word. :-)
Well I would get screenshots working one way or another, and show us what it is. The exact character may give a clue. I looked up my Unicode book and couldn't see anything quite like you described.
You said triggers stopped working. Was that triggers with backslashes in them? Or all triggers?
It vaguely reminds me of the problems I had trying to play Oblivion under Windows Vista. There was a "cheat" key (tilde, or ~) which brought up a command window where you could type things. This worked perfectly under XP, but simply did nothing on Vista. The funny thing was, you could type ~ into notepad or Word, or any other program.
I spent hours trying to fix that (without success). There were suggestions that some infra-red remote driver was responsible.
All I can suggest is, if this is a second-hand PC, that some software someone installed is catching the backslash key.
You are probably best off reinstalling Windows anyway. If this isn't a PC you started with, who knows what malware or viruses are on it?