If your Windows 10 installation is behaving unusually such as broken built in modern applications, you can perform a repair install to fix the problem. A repair install installs Windows over the existing installation of Windows 10 on your hard disk, using your installation DVD or Installation media file. Performing this can repair broken system files and simaltaneously preserving files,applications etc.
Prerequisites:
- A windows 10 ISO file which you can download from here.Make sure it has the same language,edition and architecture. For how to download ISO file, see method #3 here.
- A backup of most important files.
- A Windows 10 OS that boots to the desktop-safe mode or advanced recovery options would not work.
Things that would be removed:
- All custom fonts and customized icons.
- All Windows updates.For example if you are using an ISO of build 15063.488, then you need to apply all the updates released from 15063.0.
Steps:
- First of all open the Installation file downloaded from Microsoft's website.It would mount as a virtual drive-F:/ here and the contents would open in a new window.
- Then double click the setup.exe named file and it should show you preparing screen:
- The next step is to accept the license agreement:
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Then after some progress,it would prompt you with the confirmation.Make sure there is a tick against Keep files,apps and settings as shown:
- Sign in to your account by entering your Password first:
- You can either use default settings or customize them according to your wish.If you wish to change the default ones,choose customize your settings at the bottom right.
- When finished,it would apply your settings and then it might ask you for signing in again.
- That's it,you have done a repair Install.You can verify your build number by typing in winver in run dialog box.
Alternate
For doing a repair Install,you can also use Media creation tool.It can be called as a more automated process as you have to do nothing.It would first download an ISO and then automatically do a repair Install.
- First of all Download Windows 10 Media Creation Tool.
- After the download finishes,open the tool and select upgrade this PC now as shown:
- Sit back and relax,your computer would do the steps described above automatically till logging in.
Miscellaneous
- The older windows installation on which the newer has taken place is moved to windows.old folder in drive where windows is installed.It might take gigs of space,especially when you have a large number of programs.It would delete automatically after a month,but if you want to delete that manually do the following
- Open disk cleanup from start>All apps>Windows administrative tools.
- Choose the drive where windows is installed,like C:/
- After the first scan it does and shows the result,click cleanup system files at the bottom left.
- Then check the box older windows installations in the list,like the following:
- Then click on OK and windows would remove the files.









