Wow! is Office 2013 a major let down and a waste of money. The save/save as interface awful, non-human factors appropriate (are the new coders not trained in HF best practices anymore) now the system locks up, and when it restarts it renames your files to the names of other files you had open. In the last seven hours I've lost three spreadsheets due to this new feature.

Given Microsoft is a legitimate company and I am a paying customer I think I'm going to look into litigation as important files have been destroyed by the software.