Reinstall Windows by only wiping the C: partition?

[steffeeh]

Long story short, my brother is unable to boot into Windows (including safe mode) and have no external backup at the moment (Y I K E S, I know). We've tried a bunch of stuff but nothing works and we're down to doing a clean Windows install from a bootable installation media.

Apparently he has divided his SSD into two partitions with the standard C : only containing OS and installed programmed, and then a D : partition containing all personal files.

 

Is it possible to only wipe the C : partition with bootable installation media without touching the D : drive? IIRC when you use a device containing a Windows installation to reinstall Windows you just enter the setup and format all partitions and erase them if you fully want clean it all up - shouldn't it be possible to just format the C : partition to install a fresh Windows without losing data on the D : partition, even if they're on the same physical drive?

[Electronics Wizardy]

Make a image of that drive first, then install.

 

But if you boot into the install, you can pick the partition and other data on other parittions is fine.

[steffeeh]

So the data on D : will go unaffected if I only format C : then install on C :?