無法安裝itunes

[tib825]

請問各位前輩
安裝itunes一半
跳出
"An error occurred during the installation of assembly 'Microsoft.VC80.CRT,version="8.0.50727.4053",
type="win32",publicKeyToken='1fc8b3b9a1e18e3b",processorarchitecture="x86".
Please refer to Help and Support for more information. HRESULT:0x800736FD."

使得itunes無法安裝完成
請問原因何在
爬很很多篇文章
搞不懂
可以請各位前輩給點意見
拜託
(驚)