We’re having major problems on our home computer. When we turn it on, we get the following error message: ‘ERROR: Could not execute Main: The system cannot find file specified.’ Plus there are times when we cannot open any files or folders. Is anyone familiar with this? 
EAG
Try the link below
http://java.com/en/download/help/wjview.jsp
That link suggests a spyware/adware remover, if you don’t have one already you can get a good one here
P.S. In futer it would help to provide your OS (Windows Xp or whatever).
–lee