I assembled a desktop computer in 2001 or so whenever Windows XP launched. I was so happy when it booted to desktop in 15s. Over the many years I kept up to date antivirus and Windows service packs and updates. I also replaced various hardware lastly with a dual core i5 and appropriate motherboard. Boot times grew and grew to about 3 minutes. Because of that, I wouldn't' use it often, just a smartphone more because it was always on.
April 2014 when XP systems were rumored to instantly explode and all the private data would be held for ransom, I bought an SSD and Windows 8.1. Now I'm back to 15s boot to desktop.