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.
If that doesn't work, Leo advises running the Windows System File Checker. Go to the command line and type "sfc /scannow" and hit enter. Let it run and have a Windows disc handy.
Another option is to run the Windows installer, which prompt him to repair Windows. He should say yes to this. The worst case scenario is that he may have to back up his data, format the drive and reinstall Windows from a known, good source. Then run all of the updates.