I installed windows 10 on a 64gb, can i still use the extra space even if windows 10 is 8gb of space only?

[GabNerf]

I Have a 64gb but installed a windows 10 installer but not sure if i can use the extra space for other purposes such as storing movies or files. or i need to format it to use it again?

[Lurick]

If you mean you put a Windows 10 installer on a USB, then yes you can put other files on there as well.

[dj_ripcord]

So you have a 64GB flash drive correct? If there is a Windows 10 Installer image on the drive, plug it into a working PC, and format it. All that storage will now be available.
The drive was partitioned to have just the Windows 10 image on it, and then reduced to no other files could be written to it. Just format the drive and use it however you like. It's easy to make new Win 10 installation media with Windows' media creation tool.

[Lurick]

7 minutes ago, dj_ripcord said:

The drive was partitioned to have just the Windows 10 image on it, and then reduced to no other files could be written to it.

Not true, Windows media creation tool leaves the remaining space untouched and doesn't format or partition the drive aside from converting to NTFS (and of course wiping it before starting).