安装.net framework 4.0失败，出现HRESULT 0xc8000222错误代码
1.开始-运行-输入cmd，运行命令 net stop WuAuServ
2.开始-运行-输入 %windir% ，按enter
3.在打开的目录找到SoftwareDistribution，重命名为SDold或者删除即可
4.开始-运行-输入cmd，运行命令 net start WuAuServ
重新安装.net framework 4.0，应该就可以了
Silverlight_Tools for vs2008sp1安装失败
DOCUME~1ADMINI~1LOCALS~1TempSilverlight Tools RTWSilverlight.2.0_Developer.exe) failed with 0x80070643 - 安装时发生严重错误 .
Final Result: Installation failed with error code: (0x80070643), 安装时发生严重错误
Original exit code: E:DOCUME~1ADMINI~1LOCALS~1TempSilverlight Tools RTWSilverlight.2.0_Developer.exe returned non-MSI error code: 0x5de - 事件日志文件已满。
Exe (E:DOCUME~1ADMINI~1LOCALS~1TempSilverlight Tools RTWSilverlight.2.0_Developer.exe) failed with 0x80070643 - 安装时发生严重错误 .
PerformOperation on exe returned exit code 1603 (translates to HRESULT = 0x80070643)
Exe (E:DOCUME~1ADMINI~1LOCALS~1TempSilverlight Tools RTWSilverlight.2.0_Developer.exe) failed with 0x80070643 - 安装时发生严重错误 .
PerformOperation on exe returned exit code 1603 (translates to HRESULT = 0x80070643)
此问题需要卸载之前所安装的任何Silverlight版本即可。