OP here. I'm surprised at all the reports of multiple gigs worth of old updates being deleted. When I ran it, I only removed about 300mb. I ran it on a mates computer today (of which I look after for them, ie update, cleanup etc) and again it was only around 300mb. I'm not sure whether this is because I have always checked through exactly what updates I install and I have never installed any Windows Defender Definition updates or hardware drivers through Windows update. Can I assume this is the reason?