First there is no bit version 2008 secondly according to the below article from Technet it clearly mentions that
SQL 2005 is not supported by Windows 2008 or 2008.the only supported Operating platforms are as follows
Microsoft Windows 2000 Server with Service Pack (SP) 4 or later; Windows Server 2003 Standard Edition, Enterprise Edition, or Datacenter
Edition with SP 1 or later.
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