Without launching GigaStudio, launch the "GigaStudio Configuration Manager."
Click on the "Rewire/Plugins" tab.
According to the Giga User's Manual (have you read it?), it says:
The Configure Plug-ins dialog is helpful for troubleshooting as well as scanning for new plug-ins and viewing their types and capabilities. Click a plug-in to highlight it in the list. Then you can view its capabilities, add it to the blocked plug-ins list, or remove a blocked plug-in. One button enables you to unblock all blocked plug-ins.I can't open Giga right now, so I'm not sure where else plug-ins (or start-up options) are dealt with in the "GigaStudio Configuration Manager," but I think there's a way to have Giga block troublesome plug-ins during the program launch.