SQL Native Client 卸载不完整导致重新安装SQL 2005 STA失败

由于原SQL 2005 ENT安装程序丢失，从SP2升级SP3时出现错误，找不到合适的安装源，卸载时也需要原安装程序，没办法使用Windows Installer Clean Up卸载所有SQL相关程序，手动删除注册表中的SQL键值和剩余的残留文件。当使用手中的SQL 2005 标准版安装时出现以下错误。
SQL Server 安装程序无法连接到数据库服务进行服务器配置。 错误为: [Microsoft][SQL Native Client]客户端不支持加密。
有关具体信息，请参阅服务器错误日志和安装日志。有关如何查看安装日志的具体信息，请参阅 SQL Server 联机丛书中的“如何查看安装日志文件”。
重试多次依然提示此错误，在虚拟机测试安装正常，估计SQL Native Client没有卸载干净，导致出错。检测对比SQL Native Client相关注册表，导出虚拟机的SQL Native Client注册表，然后导入问题机器，点击重试正常继续安装。这里需要把相关的键值改成自己的主机名。

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indows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\SNI9.0]
"ProtocolsSupported"=hex(7):73,00,6d,00,00,00,74,00,63,00,70,00,00,00,6e,00,70,\
  00,00,00,76,00,69,00,61,00,00,00,00,00
"ProtocolOrder"=hex(7):73,00,6d,00,00,00,74,00,63,00,70,00,00,00,6e,00,70,00,\
  00,00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\SNI9.0\GeneralFlags]
"NumberOfFlags"=dword:00000002

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\SNI9.0\GeneralFlags\Flag1]
"Label"="Force protocol encryption"
"Value"=dword:00000000

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\SNI9.0\GeneralFlags\Flag2]
"Label"="Trust Server Certificate"
"Value"=dword:00000000

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\SNI9.0\LastConnect]
"server\\sqlexpress"="0:lpc:server\\sqlexpress"

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\SNI9.0\np]
"DLLname"="SQLNCLI"
"NumberOfFlags"=dword:00000000
"NumberOfProperties"=dword:00000001
"ProtocolName"="Named Pipes"

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\SNI9.0\np\Property1]
"Name"="Default Pipe"
"Value"="sql\\query"

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\SNI9.0\sm]
"DLLname"="SQLNCLI"
"NumberOfFlags"=dword:00000000
"NumberOfProperties"=dword:00000000
"ProtocolName"="Shared Memory"

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\SNI9.0\tcp]
"DLLname"="SQLNCLI"
"NumberOfFlags"=dword:00000000
"NumberOfProperties"=dword:00000003
"ProtocolName"="TCP/IP"

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\SNI9.0\tcp\Property1]
"Name"="Default Port"
"Value"=dword:00000599

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\SNI9.0\tcp\Property2]
"Name"="KEEPALIVE (in milliseconds)"
"Value"=dword:00007530

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\SNI9.0\tcp\Property3]
"Name"="KEEPALIVEINTERVAL (in milliseconds)"
"Value"=dword:000003e8

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\SNI9.0\VIA]
"DLLname"="SQLNCLI"
"NumberOfFlags"=dword:00000000
"NumberOfProperties"=dword:00000002
"ProtocolName"="VIA"

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\SNI9.0\VIA\Property1]
"Name"="Default Server Port"
"Value"="0:1433"

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\SNI9.0\VIA\Property2]
"Name"="Default Client NIC"
"Value"="0"

[HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBCINST.INI\SQL Native Client]
"UsageCount"=dword:00000001
"Driver"="c:\\WINDOWS\\system32\\sqlncli.dll"
"Setup"="c:\\WINDOWS\\system32\\sqlncli.dll"
"APILevel"="2"
"ConnectFunctions"="YYY"
"CPTimeout"="60"
"DriverODBCVer"="09.00"
"FileUsage"="0"
"SQLLevel"="1"

[HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBCINST.INI\ODBC Drivers]
"SQL Native Client"="Installed"

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\90\Bootstrap\MSIRefCount]
"Uninstall"="{11111111-1111-1111-1111-111111111111},{0BD4AC90-7599-4946-A4BA-9EF751A94765},{C8F010B2-134A-4D94-974C-080847EE7405},{ECFD3691-87C0-4D6F-A056-663DB104B671},{4E6AEBB6-EDB6-437B-AAE7-998599D340AF},{8F891DE6-CC63-4991-9554-917D543B23C0}"

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可能是卸载SQL Native Client时没有删除三个相关文件sqlncli.chm、sqlncli.dll、sqlnclir.rll造成的；由于卸载重装一次SQL2005需要时间太长，故没有最终确认。安装SQL2005时还需注意Microsoft .NET Framework 2.0 SP2框架环境必须正确安装。