Errors in the SQL server install typically occur because the install is attempted from an expanded/extracted iso image of the installation CD vs directly from the CD.

Unfortunately, once these install errors occur, you typically end up with a partial install. This is also the case where you have a previously installed version of SQL server, that installed other client components (SQL native client, Visual Studio and SQL managment studio). These items share some installation compnents that have client compatibility issues.

Corrective action is to completely uninstall the SQL server components and reinstall from a CD.