Open file using file path in Datagridview

[stable]

Hello,
I'm new to vb.NET.
I have a datagridview and one of the columns contains the filepath of files in a directory. I would like the user to be able to click the cell to open the file. Included in the filepath is the filename which contains the file extension (e.g. .txt, .doc, xls, jpg etc).

My problems are that I don't know how to pick up the value of the filepath and then how to open the file.

Also how can I determine that the application is not installed on the client machine?

Any help would be much appreciated.

Cheers
Stable

 

[stable]

I forgot to mention that this is a windows application not a web one.

cheers
Stable