Yes it is 10122 ... I started with a clean install on a separate SSD a few builds back. I didn't get in on the first one, maybe first two.
I do not dual boot.
I reboot and go into my BIOS ( actually the new system E something can't remember right now but I'm high and it's bedtime ) and tell it to switch boot drives.
Keeps everything separate.
Remember too this is on a desktop machine. Don't know if people are having more trouble with SP's than desktops or vice versa.
But I didn't do anything special.
Went into the settings / update and there was a Language Pack update and after that I went back in and then it gave me the build update and I just walked away and kept an eye on it and didn't touch it until it was done.
Except for clicking Reboot Now instead of waiting till later.
Also, I'm running Intel CPU not AMD which they are having trouble with.
I hate AMD and will never buy one of those again. Bad experience back about 97 with AMD. Always seems to be compatability problems with them.
Okay, first, don't mean to be insulting but did you check in the lower-right-hand corner of the desktop to make sure it's 10122? Just had to check since you're only the second person here able to install.
Second, if it really is 10122, how did you install? Is yours Win8.1 > previous build > 10122, or Win10 clean install > 10122? Just want to see if there's anything in your configuration that made it work for you and not for us.