I don't know if these two problems are related but as of recently i can not run youtube videos when loaded with Mozilla. They will work fine using Google Chome and Opera. Also, at about the same time I noticed I can not unistall programs as my Install/unistall utility program seems to be missing. When I attempt to unistall a program, I get a Windows Installer message saying "The Windows Installer Service could not be accessed. This can occur if the Windows Installer is not correctly installed. Contact your support personnel for assistance" My computer is a HP Pavillion dv7_1183cl and uses Vista Home Premium . It is about 2 years old.