I have a old 2 tier client/server accounting application that runs our business. The application uses flat files as a database rather than SQL. I haven't been locate any information that suggest that this application could run on Azure. This a COTS application,
so their can't be any porting to user the features of Azure. The question I have is 'can this 1st generation client server app run on Azure without modification?
The " 2 tier client/server accounting application" is that mean your COTS application is desktop applicatin? For desktop application, the recommended way is presist client-side application and migrate computing and storage function on Windows Azure,
for example, use SQL Azure to manage data, and publish a service to handle something.