Question reusing space of primary partition/former dual system

[cris_me]

when I bought this hdd, a friend recommended I go for the dual OS, to keep the old windows in case I don't like the new one. I was young and stupid and... now I have a so called "primary partition" of 32 gb doing nothing and everytime I start the PC, it asks me which system I want - although there is just one now/ Windows 10. It's annoying. And it's 35gb that could be MINE

the Disk Management application in Windows 10 gives me the option to format that partition (H now). What would that do? would it get rid of the ...whatever OS remnants there are there and stop asking which OS I want? will I be able to use that space, maybe include it in another partition? will it ...do soemthing bad?

windows is on C now. the one I want to get rid id is H.

I can't attach a pic. I will try later. Hope you guys understand what I'm talking about anyways.

 

[cris_me]

https://imgur.com/a/8MzaTYR

View: https://imgur.com/a/8MzaTYR

 

[popatim]

You'll need a partitioning App to make that part of one of the other partitions. Windows itself can only add space to an existing partition if the empty space is directly right of it. For example that last partition can extend into that tiny bit of space at the end (If you don't have optane which needs that space) I would suggest backing up the whole drive or imaging it first. Sometimes these programs royally screw up.

As for removing the OS selection, click the start button and type system configuration. When it opens, go to the Boot tab and remove the non-existant OS.