A family of Microsoft word processing software products for creating web, email, and print documents.
If you ask Google about dw20.exe, you'll find that it's part of the Windows error reporting system. The dw20.exe itself is not part of the problem, it's just saving a report of whatever the problem really is. (Of course, Microsoft could have made the message an explanation that ordinary mortals could understand, but that seems to be beyond their ability.) The lockup, on the other hand, is the result of the real error -- whatever that is.
A good start would be to go to the Windows 8 start screen, type error, and click Settings. One of the results is "Find and fix problems". Click that. The resulting Troubleshooting program has a lot of links to look at.