If you have ever had to do phone support, you will understand how hard it is sometimes to visualize your client operating systems program. What really would help is if you had that program or OS in front of you.
This is where sites like Chasms.com and NetworkOverload.com can help. These sites give you a basic visual emulated environment that will allow you to walk through the required steps to solve your clients issues. Both sites contain most of the major computer operating systems as well as other applications.