Dear abaco,
Open your metabase.xml, which is located in 'c:\Windows\System32\Inetsrv', find the line "AspMaxRequestEntityAllowed" and change it to a value to suite your needs.
Note: Editing the metabase.xml file requires shutting down of IIS before you can edit the file.
For more information on the AspMaxRequestEntityAllowed or the metabase.xml file, see the Microsoft documentation or click the link below.
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/iissdk/html/99b8a8bd-f9e7-43a8-b4cf-1186e2b3e9e2.asp
For IIS6.0 users, the AspMaxRequestEntityAllowed property specifies the maximum number of bytes allowed in the entity body of an ASP request. If a Content-Length header is present and specifies an amount of data greater than the value of AspMaxRequestEntityAllowed, IIS may return a 403 error response.
Please follow the steps below.
1. Stop the Admin Service.
2. open file "c:\Windows\System32\Inetsrv\MetaBase.xml
3. change the AspMaxRequestEntityAllowed to "100000". You can enter another value to suite your needs.
4. save the file.
5. restart the service.
Keep me posted.
Thank you for asking