Open LanSweeper Configuration Utility
Click on Premium Version tab
Click on Product Keys tab
Click in box just under 'Product' and type name of product
Click in box just under 'Regkey' ,copy and past text from http://www.lansweeper.com/kb/licensekeys.aspx for the path of Visio 2007 Pro (I've also tried manually typing the path)
Hit enter - which then, the new line is added below
I then select any other line items within the list and that error pops up