We had a powerpoint emailed out to everyone in our building. Some of the machines are Win 7 and most are XP. Two of the windows 7 machines had a serious problem right after running the powerpoint. They associated EVERY executable with one program: Picture Viewer. Uninstalling MS Office and rebooting fixed one of the machines but not the other. No other machines have shown any symptoms and almost everyone ran the same powerpoint. No viruses have been found.
So, why did this happen, why Windows 7, and how can I fix this second machine?