My suggestion would be to obtain the latest ISO for installation. There was a huge update in November 2015 to build 10586 from build 10240.
Then perform and in-place upgrade repair. That is to say...... upgrade it again, overtop of itself from within your current install, just double click setup.exe in the installation media. Just be sure to check the little box to get updates as part of the upgrade process.
That will generally keep all your programs, data, drivers and such safe, but.....
I would still create a disk image before going forward.
https://www.windows10forums.com/threads/please-for-your-own-peace-of-mind.794/
Installation media can be obtained here
http://www.microsoft.com/en-us/software-download/techbench
Choose Windows 10 from the top of the first drop down list (not single language version at bottom).
Then your language and the bit version that is appropriate for your system matching your currently installed bit version.
If you already have the ISO you can simply mount it from within Windows 10 and run setup.exe from there.
Neosmart has a pretty good article on it here
https://neosmart.net/wiki/windows-10-repair-installation/
You can skip the first couple paragraphs where they are promoting their recovery CDs and drill down to the meat of the article below.