1. 修改工程扩展名为.sln类型的文件
用记事本或是其他文本编辑工具打开扩展名为.sln类型的文件，比如我们打开KeyboardAssistant工程下的sln文件：
Microsoft Visual Studio Solution File, Format Version 10.00
# Visual Studio 2008
Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "KeyboardAssistant", "KeyboardAssistant\KeyboardAssistant.vcproj", "{77F63531-DD50-4363-9BCF-F124FEA91764}"
EndProject
Global
GlobalSection(SolutionConfigurationPlatforms) = preSolution
Debug|C5000W (ARMV4I) = Debug|C5000W (ARMV4I)
Debug|CW7000 SDK (ARMV4I) = Debug|CW7000 SDK (ARMV4I)
Release|C5000W (ARMV4I) = Release|C5000W (ARMV4I)
Release|CW7000 SDK (ARMV4I) = Release|CW7000 SDK (ARMV4I)
EndGlobalSection
GlobalSection(ProjectConfigurationPlatforms) = postSolution
{77F63531-DD50-4363-9BCF-F124FEA91764}.Debug|C5000W (ARMV4I).ActiveCfg = Debug|C5000W (ARMV4I)
{77F63531-DD50-4363-9BCF-F124FEA91764}.Debug|C5000W (ARMV4I).Build.0 = Debug|C5000W (ARMV4I)
{77F63531-DD50-4363-9BCF-F124FEA91764}.Debug|C5000W (ARMV4I).Deploy.0 = Debug|C5000W (ARMV4I)
{77F63531-DD50-4363-9BCF-F124FEA91764}.Debug|CW7000 SDK (ARMV4I).ActiveCfg = Debug|C5000W (ARMV4I)
{77F63531-DD50-4363-9BCF-F124FEA91764}.Release|C5000W (ARMV4I).ActiveCfg = Release|C5000W (ARMV4I)
{77F63531-DD50-4363-9BCF-F124FEA91764}.Release|C5000W (ARMV4I).Build.0 = Release|C5000W (ARMV4I)
{77F63531-DD50-4363-9BCF-F124FEA91764}.Release|C5000W (ARMV4I).Deploy.0 = Release|C5000W (ARMV4I)
{77F63531-DD50-4363-9BCF-F124FEA91764}.Release|CW7000 SDK (ARMV4I).ActiveCfg = Release|C5000W (ARMV4I)
EndGlobalSection
GlobalSection(SolutionProperties) = preSolution
HideSolutionNode = FALSE
EndGlobalSection
EndGlobal
把前面两行的内容：
Microsoft Visual Studio Solution File, Format Version 10.00
# Visual Studio 2008
改为下面的内容
Microsoft Visual Studio Solution File, Format Version 9.00
# Visual Studio 2005
2. 修改扩展名为.vcproj的文件
用记事本或其他文本编辑工具打开 sln中所包含的所有工程，即以 .vcproj 为扩展名的文件类型，即sln文件中的第3行，如果包含多个.vcproj类型的文件，则修改方法类同，从KeyboardAssistant工程的sln文件中可知只包含了一个工程，对应工程文件KeyboardAssistant\KeyboardAssistant.vcproj，因为此文件内容较多，所以只列出开始的一部分：
<?xml version="1.0" encoding="gb2312"?>
<VisualStudioProject
ProjectType="Visual C++"
Version="9.00"
Name="KeyboardAssistant"
ProjectGUID="{77F63531-DD50-4363-9BCF-F124FEA91764}"
RootNamespace="KeyboardAssistant"
Keyword="MFCProj"
TargetFrameworkVersion="131072"
>
…………………..
把其中的内容：、
Version="9.00"
改为下面的内容即可：
Version="8.00"
修改之后保存就可以用VS2005来打开了。