解决SQL server 2008 R2卸载不完全
参考地址：
http://sqlblog.com/blogs/aaron_bertrand/archive/2010/10/25/fun-with-software-uninstalling-sql-server-2008-r2-evaluation-edition.aspx?CommentPosted=true#commentmessage
正常卸载过程后，卸载安装程序时提示错误26003：因为安装了以下产品无法正常卸载
SQL Server 2008 R2 SP1 Common Files
SQL Server 2008 R2 SP1 Database Engine Shared
解决方法是在注册表中删除相应键值
位置为HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\
在其中自行寻找相应键值，套如到以下bat文件中运行即可
rem SQL Server 2008 R2 Common Files
msiexec /x "{234F6B0D-10AE-4BB7-B2F3-E48D4861952D}"
rem SQL Server 2008 R2 Common Files
msiexec /x "{36F70DEE-1EBF-4707-AFA2-E035EEAEBAA1}"
rem SQL Server 2008 R2 Database Engine Shared
msiexec /x "{A2122A9C-A699-4365-ADF8-68FEAC125D61}"
rem Microsoft SQL Server 2008 Setup Support Files
msiexec /x "{C0C690C8-F335-4BA4-A2AD-675EAD1DFA90}"
rem SQL Server 2008 R2 Database Engine Shared
msiexec /x "{C942A025-A840-4BF2-8987-849C0DD44574}"
rem Microsoft SQL Server 2008 R2 (64-bit)
msiexec /x "{20E42995-BBE9-4697-8394-FCDC4338706B}"
rem Microsoft SQL Server 2008 R2 Setup (English)
msiexec /x "{C3E48238-5FA0-4C82-9509-36D47E371A29}"
卸载过程中会提示错误，直接跳过。