After a recent Windows 10 update, I now get a msg that my PC did not start properly.

[InTLH]

Repeated attempts at Automatic Repair takes me back to a blue screen with the msg Computer did not start properly. When I run logfiles, results show 1 root problem, but Startup Repair cannot determine cause of the problem.

[BeemerBiker · Accepted solution]

This is an older system, probably windows 7.  

You can do a custom install of windows 10x32 and your old files will be "saved" but you will have to re-install any licensed software as described here

https://answers.microsoft.com/en-us/windows/forum/all/how-to-perform-a-custom-installation-of-window...

Note that Windows 10 will be activated automatically.  Licensed software like Office required a login to Microsoft account and a download but will activated.  It is possibly that some older software may not be activated.

[EDIT]  Did you try the "restore" where it looks for a recovery point?  

Since the problem occurred on a windows upgrade you might ask over at answers.microsoft.com 

If they sent you here then you probably tried stuff already.

If you ever do a clean install of windows I would go with 64 bit as it is  a free upgrade from 32