I recently came across a problem when uploading a document through an ASP application to an IIS 7.5 web server. When I attempted to upload the document I received an http 500 internal server error. It turns out the issue was caused by an IIS setting restricting the size of the entity-body of the ASP request.
Something I have frequently seen implemented incorrectly on Windows Server domains is time synchronization. Many admins think that by creating a GPO with a modified policy setting for 'Configure Windows NTP Client' (and using it to address an NTP source) all Servers and Clients will synchronize their time with that source. This isn't entirely true and there is actually a time hierarchy that should be considered when implementing time synchronization for each domain.