I installed the Creator's Update on my HP Stream 7 Signature Edition shortly after the update came out in April. I was having trouble upgrading through "Update and Security" also, so instead I did it using the W10M install media stored on a USB thumb drive connected via a USB-A to micro-USB OTG adapter. I upgraded from the Anniversary Update of Windows 10. Everything went smoothly.
I must say, however, that I am not happy about the performance. Whereas the tablet ran great on the Anniversary Update, now on the Creator's Update it feels sluggish. And for some strange reason, in the Netflix app, the first time I select a show it tries to play it for a minute then times out with an error. I try to play it a second time and then it plays. This happens every time I open Netflix, ever since I upgraded to the Creator's Update back in April. Because of this and the sluggishness, I am thinking about downgrading back to the Anniversary Update, but just haven't had the time to do it. I know it is not due to a lack of disk space, since I previously merged the recovery sector with the main sector and deleted the HP recovery files and I also deleted the files for the previous Windows install, so there is plenty of drive space.
If anybody has any advice on improving the Stream 7 performance on the Creator's Update, I would love to hear it.