Can't delete paritions in Disk Management

[Saint Grimm]

My old drive that I'm now going to use as extra storage has 4 partitions, "System" "OS(E: )", one without a name and 17.14 GB unallocated space.

I'm unable to delete the un-named partition or the system partition. The one without a name doesn't even give the option. When right clicking it it only gives the "help" option. When telling it to delete the "System" partition, it says "Windows cannot delete the active system partition on this disk". However, my computer's OS is running from my new disk, not the old one.

There is also no option to extend any of the 3 partitions, even though there is over 17gb of unallocated space. Anyone have any ideas?

EDIT: Looking at my current drive, I also noticed that windows didn't automatically partition it for the system install as I had though it would. So it's 1863.01GB NTFS - (Boot, Page File, Active, Crash Dump, Primary Partition). But it doesn't say system like the "System" partition does on the old disk.

However, I know that it's using the windows from the new HDD, because it was windows 7, a clean install and upgraded to windows 10. If the clean install was put onto the old disk, it would have deleted all of my stuff, which it didn't and I have now moved to my new disk. (Hope that's not explained in a confusing manner)

EDIT2:

 

[ss202sl]

What happens if you disconnect the old disk(my guess is it won't boot). You need to re-install the OS on just the new disk. Right now it's booting from the old disk(boot partition and system reserved), that is why you can't delete them 0 they are being used by the system.

 

[SBMfromLA]

When I encounter disks or partitions that are locked... i just take the quick out way. I boot up from my Windows DVD... go to the screen where you install Windows and select ADVANCED... then at this screen I'm able to access my disks and partitions without any trouble... You could do the same... I would just delete all the partitions on that drive and create a single new one.

 

[Saint Grimm]

I'm reinstalling windows 7 now, I had both drives hooked up the first time, which I'm guessing may be the cause it didn't create the system partition - It knew the other drive had them and didn't need them maybe?

Unhooked the old drive and doing the install. Will update afterwards.

 

[Saint Grimm]

reinstall without the old HDD hooked up gave me a system partition. Should be able to take it from here! Thanks!