Heres the problem. I had this NTLDR error a few days ago which i fixed with a usb stick, i got back into windows and removed some programs then started playing Cs 1.6 (Yes i know old game) I got into a server and i lag for a second the fly across the map.. When i fire guns it shoots insanely fast. Unintended speed hack? It does this for all online games, i tried it for Runescape and it does that.
I removed Internet explorer 7 since i use firefox :X
I sent a support ticket to steam with no reply yet.
Check your video settings for CS and possibly the card settings. If VSync isn't enabled try turning it on. I've seen similiar happen on older games where the hardware used far suprases what's required. It does seem odd though that it would happen in an online game.