Bill has been getting DLL errors. Leo says that the only real way to solve this is to do a complete Windows reset, which is really easy in Windows 10. Bill can just press the Start button, then select Settings > Update & Security > Recovery. Under "Reset this PC", he should select "Get Started".
Kevin has a friend who is having trouble with apps like Adobe Reader crashing intermittently. Leo says that it sounds like bit rot. Some programs like Adobe Reader use the same dynamic link library (DLL) and that if that get corrupted, it make sense that anything else that uses it will crash. So Leo suggests removing Reader and then downloading and installing the latest version. He should also update to the latest version of Internet Explorer.
Jim is running Internet Explorer 10, and keeps getting error messages saying that "Internet Explorer has stopped working". There are a lot of things that can cause a browser to crash. He should first update Internet Explorer to version 11, which is the latest. He'll have to go to Windows.com and install it from there, because it won't be in his System Updates yet. If that doesn't fix it, he should reset the browser.