Normally it should be installed with the set-up of SQL Server or the OS, if I'm not mistaken.
But there is no 64-bit version and according to this already very old article, this provider is deprecated.
http://msdn.microsoft.com/en-us/library/ms810810.aspx
If you install the Oracle client, you'll get the Oracle OLE DB provider, which is also available in 64-bit.
MCTS, MCITP - Please mark posts as answered where appropriate.
