Getting rid of an old Windows 10 installation

[Schism]

I thought it would be a simple issue, but alas, it's not. So, I have to ask for help. My old install of Windows 10 (upgraded from Win7) became a mess recently, with a lot of driver issues. So, I've decided to do a fresh reinstall. I also bought an SSD (256gb basic Samsung). I installed fresh system on it and wanted to format my old HDD to get that 1TB of storage. It used to be 3 partitions: 250gb windows, 500gb for games and stuff, 250gb for mostly torrents and other crap. Second and third partitions I did a format no problems. The issue is with the old Windows (C:) partition. I can't format it through disk management and everytime I boot up, I have to choose the new installation of windows which pretty much doubles the boot time. The question is: how do I format that partition and get rid of the old windows installation?

[Murasaki]

Have you tried it with the DISKPART command line tool?

[Schism]

4 hours ago, ModuleLFS said:

Have you tried it with the DISKPART command line tool?

Wouldn't DISKPART clean the whole HDD and not just the partition that I want? I only used it to change a bunch of discs to the format accepted by W7 (GPT to MBR iirc), but I was always cleaning up everything. If there is a way to clean only one partition, it'd work for me, I guess.

[Murasaki]

Yes you can delete individual partitions on volumes. Though you must be careful not to select the wrong volume, data loss isn't pretty.

 

Open the command prompt and execute DISKPART, after that list disk, it will show you all available drives each with a number, type select disk n (n being the number of the volume your drive is), then list partition, see which partition number contains the windows insallation (most likely 1), select partition n and finally delete partition.

[Schism]

It says that partition is in use and i need to use override parameter as in the picture. Also, I was looking up the override parameter and I found this: https://technet.microsoft.com/pl-pl/library/cc730824%28v=ws.10%29.aspx which says that using it might corrupt the whole drive. How safe is it for my HDD to delete the partition this way?

[techguru]

1 minute ago, Schism said:

It says that partition is in use and i need to use override parameter as in the picture. Also, I was looking up the override parameter and I found this: https://technet.microsoft.com/pl-pl/library/cc730824%28v=ws.10%29.aspx which says that using it might corrupt the whole drive. How safe is it for my HDD to delete the partition this way?

you best option is to copy the data you want off the drive

delete all partitions

and remake them

then copy the data back to where you want

[Murasaki]

20 hours ago, Schism said:

It says that partition is in use and i need to use override parameter as in the picture. Also, I was looking up the override parameter and I found this: https://technet.microsoft.com/pl-pl/library/cc730824%28v=ws.10%29.aspx which says that using it might corrupt the whole drive. How safe is it for my HDD to delete the partition this way?

You can try booting Windows in Safe Mode with Command Prompt (spam F8 before windows starts loading) and do the same task, not sure if its still going to be in use.