Same here I tell them that i just replaced my windows and the open and close just fine. When they say it is your computer and the IP is sending an error I ask them what my IP address is. Then they say it is messing up their servers so I tell them to block that IP address
The scammers mine social media sites like Facebook to glean enough information to make the ruse believable. This is probably how they knew the relationship between the grandson and the recipient of the scam, and that the grandson had been at a wedding. My father was called from one of these people at least five years ago with a similar story, so the scam isn't new.