.net3.5 sp1安装出错,求解读异常日志是什么意思

.net3.5 sp1安装出错,求解读错误日志是什么意思
安装.net3.5sp1出错.
日志如下:


[09/01/11,02:40:23] Microsoft .NET Framework 3.0 SP2 x86: [2] Error: Installation failed for component Microsoft .NET Framework 3.0 SP2 x86. MSI returned error code 1603
[09/01/11,17:52:56] Microsoft .NET Framework 3.0 SP2 x86: [2] Failed to fetch setup file in CBaseComponent::PreInstall()
[09/01/11,17:52:56] setup.exe: [2] ISetupComponent::Pre/Post/Install() failed in ISetupManager::InternalInstallManager() with HRESULT -2147467260.
[09/01/11,17:52:57] setup.exe: [2] CSetupManager::RunInstallPhase() - Call to Pre/Install/Post for InstallComponents failed
[09/01/11,17:52:57] setup.exe: [2] CSetupManager::RunInstallPhaseAndCheckResults() - RunInstallPhase() returned a NULL piActionResults
[09/01/11,17:52:57] setup.exe: [2] CSetupManager::RunInstallFromList() - RunInstallPhaseAndCheckResults failed [2]
[09/01/11,17:52:57] setup.exe: [2] ISetupManager::RunInstallLists(IP_PREINSTALL failed in ISetupManager::RunInstallFromThread()
[09/01/11,17:52:58] setup.exe: [2] ISetupManager::RunInstallFromThread() failed in ISetupManager::RunInstall()
[09/01/11,17:52:58] setup.exe: [2] CSetupManager::Run() - Call to RunInstall() failed
[09/01/11,17:52:59] WapUI: [2] DepCheck indicates Microsoft .NET Framework 3.0 SP2 x86 is not installed.
[09/01/11,17:53:00] WapUI: [2] DepCheck indicates Microsoft .NET Framework 3.5 'package' was not attempted to be installed.
[09/01/11,17:53:00] WapUI: [2] DepCheck indicates Microsoft .NET Framework 3.5LP - CHS was not attempted to be installed.
[09/01/11,18:03:45] Microsoft .NET Framework 3.0 SP2 x86: [2] Error: Installation failed for component Microsoft .NET Framework 3.0 SP2 x86. MSI returned error code 1603
[09/01/11,18:05:13] WapUI: [2] DepCheck indicates Microsoft .NET Framework 3.0 SP2 x86 is not installed.
[09/01/11,18:09:14] Microsoft .NET Framework 3.0 SP2 x86: [2] Error: Installation failed for component Microsoft .NET Framework 3.0 SP2 x86. MSI returned error code 1603
[09/01/11,18:10:43] WapUI: [2] DepCheck indicates Microsoft .NET Framework 3.0 SP2 x86 is not installed.


------解决方案--------------------
先下载 Microsoft .NET Framework 3.0 SP2 安装试试
http://www.microsoft.com/downloads/zh-cn/details.aspx?familyid=24b72300-3e17-4b5d-8954-44fd35252630&displaylang=zh-cn