My OS is win 7 enterprise and I am using a Dell 6500 laptop 64 bit. From time to time now I get a missing dll whenever I boot up. tried to fix it using a dll-files client that I downloaded, but the problem persists. the files are :: MSVCR100.dll or MSVCR120.dll. Hope the Experts can please explain what is happening and how to remedy this. My anti virus is Security Essentials and antimalwarebytes which is out of date, and I did not update it, as it conflicts with Security Essentials. Thank u and regards.