I have a module that attaches a pdf document that has been auto saved to the default location of the user computer. Since the default location on each computer will be different. I need the code to pick up this location.

What is the method for referencin the default path on a user computer

The default path to what? If you have a module that attaches this document, get the path from that module. Or do you mean you have a module that fails to attach this document?

A pdf document is created using adobe, this saves teh fiel in the default windows location. I need the module to find the default windows location and attach this file according to the user.
At the moment my moduel requires a filepath, i cant hard code a path into this, as the default location where the pdf file is saved, varies according to the user

It seems to me that you are looking for where your Adobe program saves it's files. Perhaps you can automate Adobe on the user's machine and read a setting for where it saves its files by default, but still, couldn't a user save a file anywhere?

Environ("HomePath") will return a default save location, but not necessarily the default save location. Most programs have default save locations that vary from program to program.

A better solution is to have your users store PDF files to a defaults PDF location (C:\PDF\, perhaps).

You may want to loop through the Environ commands and see if another path (there are a few in there) better suits your needs.