Silverlight cannot be displayed in IE

Considering the difficult problem to solve and the significance of the solution, this issue is posted on the homepage.

Problem: Silverlight cannot be displayed in IE and a prompt is displayed for download. It is normal in Firefox.
System Environment: Vista,
IE7
Corresponding version: 1.0 RC,
1.0 RTW, 1.1 Alpha Aug./Sept. Refresh
Description: On the page containing Silverlight, the system prompts you to download and install Silverlight. After installation, the system displays that the installation is successful. After the page is refreshed, the system still prompts you to download and install Silverlight; however, when you open Firefox to access this page, the page is displayed normally. Note: To use the Administrator permission (shortcut menu, run
As administrator)
Solution Process:
If you try to uninstall, reinstall, or restart, the problem cannot be solved. The problem seems simple, but it cannot be solved. The first thing that comes to mind is whether you can get some log or debug information, but you can't find a method. Then, at the prompt of Silverlight product department Xiao Ying, I referred to some materials, use the following method (you can view many problems in the future ):
 
1. download the latest Microsoft Process
Monitor.
2. Start IE and open a page containing a Silverlight program.
3. Open Process Monitor and select process name is iexplore.exe (figure 1 ).

4. Refresh the page that contains the Silverlight program.
In this case, iexplore.exe tries to access hkcr/agcontrol. agcontrol, but the access result is Access Denied (figure 2 ). This is the problem!

6. The problem is discovered, but the solution is not that simple. Open the registry and try to modify the permissions of hkcr/agcontrol. agcontrol? Access is denied, and cannot be modified in any way.
7. After checking the information, I finally found that there was a problem with the permissions of hkcr (the permission user list is empty, different from other machines), resulting in a problem with the installed agcontrol. agcontrol! Find a normal Vista Registry Key (thanks to Felix) and set the hkcr permission for your machine (Figure 3 ).

8. Uninstall Silverlight and reinstall it. OK!

Conclusion: It seems to be a problem with the Silverlight installation program. It is actually a problem with the Registry hkcr itself. Process
Monitor is a good tool for debugging programs.
Reference: Currently, there are few references for Silverlight on the Internet. Only the official forum of Silverlight has some references:
Http://silverlight.net/forums/p/600/11562.aspx
Http://silverlight.net/forums/t/3391.aspx