If your Microsoft Office products are freezing, lagging or behaving strangely, the issue may be with hardware graphics acceleration. We’ve seen issues involving Windows 8 and Nvidia Graphics chipsets, in all cases, disabling hardware graphics acceleration in the Microsoft application solved the problem. It’s possible that a drive update will be released to fix these issues but in the mean time, here is the solution.

Disable Hardware Graphics Acceleration

http://support.microsoft.com/kb/2768648