Something I remembered...
Last year I installed Windows 8 for test and I had a problem with starting W3d too. Not sure if it had the same behavior as your, but I fix it by reinstalling W3d and in the install dialog forcing it to install the Microsoft Visual C++ runtime. For some reason the install doesn't mark it for install (maybe because there is a newest version installed), but forcing it be installed fixed the problem.
Check that please.
Last year I installed Windows 8 for test and I had a problem with starting W3d too. Not sure if it had the same behavior as your, but I fix it by reinstalling W3d and in the install dialog forcing it to install the Microsoft Visual C++ runtime. For some reason the install doesn't mark it for install (maybe because there is a newest version installed), but forcing it be installed fixed the problem.
Check that please.