during installation of self created desktop application, how to check that one of the perticular file/application have installed or not..

[Pradeep Kumar Srivastava]

Hello, Can anybody help me that, how to check, perticular files have already installed or not in local system during installation of desktop application. Actually i've created a desktop application. Now for that application, some microsoft.sqlserver files must be installed in the local system. I want that during installtion of my desktop application, there should be a way for checking that .sqlserver files have installed. If not then, installer must prompt to the user that those files must be installed for this desktop application. After this, installation should be completed. Please help me about this asap...

Thanx Deep