How to: Configure IIS7 for Web Synchronization

I have followed the instructions here.

To cut a long story short, I just cannot connect to:

https://machine/site/virtual directory/replisapi.dll?diag

I get:

HTTP Error 500.0 - Internal Server Error

Module IsapiModule
Notification ExecuteRequestHandler 
Handler ISAPI-dll
Error Code 0x800700c1 
Requested URL https://machine:443/site/virtual directory/replisapi.dll 
Physical Path C:\inetpub\SQLReplication\replisapi.dll 
Logon Method Basic 
Logon User machine\user 

When browsing to the DLL it does ask for my username and password then shows this error. We're using a self signed certificate as this is just for testing.

I'm not really a server person so don't know what is going on? There's nothing in the event logs.

Does anyone have any bright ideas of things I could try?

P.S. I also ran the wizard through SQL 2008 R2 which said it was successful (the wizard only works with IIS6) could there be a conflict between IIS6 and 7 now I have tried to set it up on both?

Ok, this was me being dumb.

After I retraced my steps backwards and unregistered replisapi.dll and moved into a backup directory.

I then removed my module mappings from IIS7.

I then ran the SQL wizard again, which copied replisapi.dll back to the directory.

I noticed it was a different size to the one I was using.

This was because I had got it from "Program Files" but being a 64bit machine the wizard got it from "Program Files(x86)" and now it works.

How simple yet frustrating!