Windows 7: Fine for gaming if you only use one input language

I take back what I wrote for a blog post saying Windows 7 is good except for Source Engine games. It's still good for Source Engine games, IF you use only one input language: English combined with a US Keyboard layout.

If you have additional input languages, Windows 7 tends to freeze Source Engine games cause you never know if the other language might pop up/switch to and try to type foreign characters in place of W, A, S, or D.

I have tested the L4D2 Demo and it ran seamlessly with only one input language used.

I will test L4D1 next and will post results on whether I was able to play "Crash Course" (a 2 level campaign) seamlessly and a full-length campaign seamlessly in an edit to this post.

Edit: I've surpassed the point where I got freezing problems in Crash Course in L4D1 with no problems. However, in the main menu the game tries hard to look for as many Steam Group Servers as it possibly can (one time I got upwards of 300-500 servers)... Even though you're not part of their group... This is probably a problem that comes and goes in Windows 7 since it only does it sporadically.

If you see blank "In-Game" fields in your Steam friends list, you might want to click the Check for Steam Updates button once, that somehow fixed it for me.

Also, be aware that Windows Firewall might block L4D2 from internet access as a FYI.

Edit #2: Played most of the Dead Air Campaign with no problems (didn't finish the campaign as it was pretty much definitively stable). Windows 7 actually has a higher CPU and GPU usage possibly due to optimizations...

Edit #3: (moved to a new post since it is very extensive)