Dual-boot Ubuntu 16.04 with Windows 7, then upgrading to Windows 10

I have a small Lenovo (ThinkPad X100e) running 32-bit Windows 7 Home edition.  I wantd to add dual-boot, then upgrade to Windows 10 to test that it won't erase my Ubuntu partition.

I first tried just running a bootable Ubuntu 16.04 LTS (long term stable) USB, and it got me into Ubuntu install, but when I got to the partitioning step the computer said okay, then shut down, and it never seemed to install.  I suspected I might need to partition first.  I pre-emptively went ahead on shrinking the Windows partition before repartitioning, following these steps as in my previous post just adjusting steps by looking in Windows 7 places for the settings.   System protection was already off and I skipped CHKDSK because Windows ran it on its own after my failed original Ubuntu automatic repartitioning attempts.  My computer also insisted on rebooting between steps 4 and 5.  Disk cleanup (step 5) took less than 20 minutes. Disk shrinking was maybe less than an hour.

I also realized during the Windows shrinking that I was trying to install 64-bit Ubuntu (the main file that downloads) onto a 32-bit computer.  I downloaded 32-bit from a mirror (there didn't seem to be an easy link on the main Ubuntu site, had to look around for it in their site) and made a new bootable USB.  I tried again.  At the partitioning step, I got a scary looking message about whether I wanted to continue with automatic partitioning (it said it will change and format some things).  I answered continue, and then I went on with set up.  That worked and I now have Ubuntu 16.04 LTS dual booting with Windows 7.

This went a lot faster than with my last dual-boot setup.  I think this was because I had Windows 7, an older laptop, and a bit more experience, and probably mostly because I cared less about whether I ruined my Windows set up. This older computer also didn't have weird boot settings that the newer one did (secure boot), nor did it have Windows 8 hibernation and fast shutdown/startup to worry about.  I also did not want to set up a shared data partition on this laptop so that did not take up any time.  So I did less prep, and it still turned out okay.  Your results may vary.

Now, the Windows 10 upgrade over the dual-boot system.  I ended up not having enough space on my Windows partition because I had some duplicate users and all their data.  I uninstalled a few large programs that I didn't use any more and then removed the two duplicate users and their data (be careful with this!  I was very sure I did not need those user profiles).  After following the various on-screen prompts, I eventually got a message that I had to log into my administrator account.  I did so, waited for the download again, and then the Windows 10 upgrade just... failed, every time, even though I was booting back into Windows 7 and not Ubuntu.  With the error code, I found that I should be rebooting into the system recovery partition.  I did that and sure enough, it worked!  The install crashed once because my laptop overheated, but that's my laptop's problem.  I set it on an air vent in the house and the AC kept it cool enough to restore Windows 7 (Windows did this on its own).  I then started the Windows 10 upgrade again and it finished the install.  I missed a few reboots and it booted into Ubuntu, but in those instances I just rebooted and watched to select the Windows system recovery partition and it resumed where it had left off.  Windows 10 did not erase my programs or apps, so I am pleased with how this went and might even try it on my main working computer now.