Weird-looking Office bug
All the Microsoft Office programs - Word, Outlook, Excel etc - lose their soothing, sleek modern look for a weird, lo-fi, monochrome appearance, as if the graphics have been reduced to 16bit or reverted to Word 97. Most noticeable is the way that the window buttons (shrink / maximize / close) revert from their modern / 2007 to blocky low-rez versions. The really strange part is that it seems to only affect the MSOffice applications.
This "just happened" one day without any apparent system change or software update.
Where similar problems are reported across the web, various well-meaning or logical solutions are suggested around the place - toggle monitor color depth, update monitor drivers, check accessibility settings, change Office or system theme. None of these work.
The root problem is another video driver somehow grabbing control. The culprit is sometimes figured as the "SMS mirror driver", although in my case it was the "LANDesk remote control mirror driver". Find the rogue driver at My Computer -> Properties -> Hardware -> Device driver -> Display adapters. Disable this and restart your system.
It's not clear whether the problem was provoked by a sysadmin updating the driver in the background, or if it's something that just happens randomly.
Windows XP64, MSOffice 2007, multiple monitors with Nvidia drivers.