I had to install a copy of SQL Server 2005 on a Windows Server 2003 R2 SP2 x64. During installation I got a strange error saying that SQLncli_x64.msi file is missing. I was pretty sure that I have the same ISO file as I did while installing SQL so many times before and without any errors… Searching the net, the solution from Microsoft forum was the right one.
Before installing SQL Server, you have to download and install Microsoft SQL Server Native Client x64 file (sqlncli_x64.msi) from Microsoft Download Center.
Note: If you’re going to install Analysis Services too, then make sure to download and install Microsoft SQL Server 2005 Management Objects Collection x64 file (SQLServer2005_XMO_x64.msi) also.