This is not what I wanted to see

Just two days into ownership of my new HP spectre and I woke up to this. A Windows Update. This sent chills down my spine. Windows 10 updates have killed two of my computers and severely hobbled another. The damn thing took its time as well.

So far I can’t see any changes but I also can;t see any damage done either. However around 10% of my available disk space just vanished. It seems I have a directory now called windows.old duplicating my current windows directory. As I have very low confidence in Microsoft updates I’m going to have to keep it around in case I need to undo the update.

Is it really necessary to update software within two days? If so what is wrong with the operating system? I’m sure those with 125 GB disks will not be happy losing 20% of their disk space so soon after purchase