COMPLETELY UNINSTALL V3.x and any VehiclePaks before installing the newly downloaded file!
Do that via the Add/Remove Programs control panel.
Then just double click on the TL4_VehPak_7_FULL.msi file and it'll install the new software.
If you want the latest and greatest hardware (which allows connection to later ECMs like the Sy/Tys and the LT1 powered vehicles), you can order the upgrade from the ORDER section of the web site. A new CD with the latest software is part of that package.
Thanks Ken. I will try that. I think Id better figure out the problem Im having with TLink while recording first though. I will start a seperate thread for it.