Installed 10 onto an SSD and want to format my HDD but nothing works

Hi all, DragonMutt again with another computer problem!

So yesterday I installed a SSD from Samsung and put windows 10 onto it via a boot disc I created
I've gone ahead and copied across all of the files that I wanted ready to reformat the HDD that I was using for the last year
I've tried hovering over it in my computer and clicking format although nothing comes of that, I'm an administrator on the computer so I don't understand why.

I have tried disk part and selecting the drive and using clean but it says I have system files on there that are in use but how could that be possible if I load the windows 10 from my SSD? I've also tried deleting the partition and shrinking it to removes files in disk management but even that yields nothing to me.\

I've now come to think that I should have disconnected the HHD while installing on the SSD but i'm not 100% sure.

I can post any screen shots when I get home from work, just wondering if people could start pooling ideas with me? Thanks you in advance!

Yes. You need to disconnect the HDD when doing a clean install to ssd

Alright! I'll give that a shot! Thank you!

U actually dont need to reinstall .. Just boot from Widnows 10 Media USB or DVD..
When u reach the screen of disk selection (where to install windows) Format your HDD there.

I think Manish's idea should work, but a MiniTool Partition Wizard 9 Boot CD/USB disk should as well and is a great Tool to have around .

The system won't let you format it as the partition likely is still marked active and boot and possibly system ( Minitool 9 will show you) so it is trying to protect itself ....

Its put some system files on the hd thats why you can format it if you did with external software it wont boot. Try with the second drive disconnected see if it will boot if it wont then Remove the hd then do a repair of windows from the usb/dvd