I had Office XP on my laptop. Uninstalled this and replaced with Office Enterprise 2007 (still running under WinXP). Seemed to install okay but laptop seems to keep "twitching" is only way I can describe it. Things seem fine then the Menu Bar in Explorer turns solid black or the sound disappears and wheel scroll won't work in Word 2007. I am guessing but it looks like a driver issue maybe. I have Googled and searched MS site but no luck so far. Any ideas? Thanks!