Cannot Install .net Framework in Windows 7

Hi, All

I've follow the link from saranspot.blogspot,

I open the command prompt run as administrator, after typing dotnetfx.exe /c:"msiexec.exe /a netfx.msi TARGETDIR=C:\Dotnet"

I got message:
Error 1310 Error writing to file:
c:\dotnet\Win\Microsoft.Net\Framework\URInstallPath\aspnet_isapi.dll
Verify that you have access to that directory.

any help

regard's