Opening a File with Process.Start outside root folder

Hello.

So, I have a webForm that has an ImageButton. This ImageButton has to open a file (said file is uploaded by the user in another web form. The file is saved to \serverNamefiles; it can be a doc file, pdf file, excel file).

So this ImageButton should open said file as you normally would. It works on debug, however when I publish my site, and run it from my localhost, it doesn’t open the file. When I click the ImageButton it just does the postback and nothing happens.

The code for the ImageButton is just:

Process.Start(fileName);

fileName has the full path of the file I want to open, in this case it has: \serverNamefilesmyFile.pdf

Why is this happenning?

Thanks in advance