If it won't initialize in Windows or stay initialized I would suspect there is a physical problem with the disk. You can search "hard drive DFT software" and download any number of them to test the disk.
The Windows installer isn't the brightest regarding installing things that would make sense to a person.
The simplest method would be backup data, disconnect all drives but the intended one for the operating system and reinstall.
The harder approach and much more technical (and there is risk in...
Well to be clear the C letter is assigned to Disk 1 (second disk), third partition and that is what you are currently booting to. You can't initialize a active disk/partition.
Are you trying to initialize Disk 0?
Exes are packed binaries that have methods that can't be referenced in other projects. DLLs are just libraries to be used by other projects. If you have the dll source you could certainly incorporate that code into a separate exe project.