I find this interesting, but I wonder if it's actually quite simple?  has anyone ever seen this?  I installed Mojo Portal via the Web Platform Installer, and now IIS 7.5 throws a 500.2 error.  The rror is the following. 

IIS 7.5 Detailed Error - 500.21 - Internal Server Error

Server Error in Application "DEFAULT WEB SITE"

Internet Information Services 7.5

Error Summary

HTTP Error 500.21 - Internal Server Error
Handler "PageHandlerFactory-Integrated" has a bad module "ManagedPipelineHandler" in its module list
Detailed Error Information

table with 2 columns and 4 rows
Module
IIS Web Core 
Notification
ExecuteRequestHandler 
Handler
PageHandlerFactory-Integrated 
Error Code
0x8007000d
table end

table with 2 columns and 4 rows
Requested URL
http://localhost:80/Default.aspx 
Physical Path
C:\inetpub\wwwroot\Default.aspx 
Logon Method
Anonymous 
Logon User
Anonymous
table end

Most likely causes:
list of 2 items
• Managed handler is used; however, ASP.NET is not installed or is not installed completely.
• There is a typographical error in the configuration for the handler module list.
list end
Things you can try:
list of 2 items
• Install ASP.NET if you are using managed handler.
• Ensure that the handler module's name is specified correctly. Module names are case-sensitive and use the format modules="StaticFileModule,DefaultDocumentModule,DirectoryListingModule".
list end
Links and More Information
IIS core does not recognize the module.

View more information ». 

What am I missing here?  Thanks for any feedback!