short version:
boot to windows PE(Windows Preinstallation Environment) and run gimagex.
if you have no boot disk but running windows, that’s OK: run “ReAgentc.exe /boottore” (need administrator privilege) then reboot.
you will boot to windows RE(Windows Recovery Environment; it is a special kind of win PE). open console, then run gimagex. it will be executed with no problems.
*** don’t forget to enter bcdboot.exe C:\windows to create bootloader entry. ***
long version:
I prefer multiple partitions for system disk. It have some advantages over 1 partition structure: you don’t need a backup, you “may” expect longer disk life(in case of SSD, because it allows you to write disk side to side.)
But I had to use 1 partition in my laptop, because of its limited space. And recently… I need re-install.
Well, re-install using wim(windwos imaging file) is quite simple: if you have multiple partitions. just boot in windows, run gimagex, apply to new partition. and make boot item to boot manager. done!
And here is the challeange: you have no enough space for another partition.
A standard way to install windows using existing wim, is creating windows installtion disk using windows AIK(or ADK, brand new name for win 8+). but I don’t want to do that for single installation.
After few hours of searching, I found intresting information: ImageX can be used in windows PE installation. Accoring to this(https://technet.microsoft.com/en-us/library/dd744320%28v=ws.10%29.aspx), In order to capture windows you must boot to windows PE, (or, you can use another windows installation. windows PE is just an “lightweight” installation) then run imagex. So it means you can use imageX in windows PE! okay, then how about gImageX?
The answer is, YES. In windows PE you can run not only command line program but also (some) win32 applications. and gimagex is one of them. so use it like in regular windows.
2017-03-15 17:12 update:
revise some sentences for easy reading.
same day, 20:15 update:
add bcdboot.exe notice