Q:

Installing Windows from a USB drive

I am installing Windows 8.1 through a usb stick. Here's how I did it:  

Download the media creation tool from MS website.  
Run the tool and get the setup stuff onto the drive.  
Insert the drive into the new computer, which btw has no OS on it.  
Go to boot menu, select boot from USB  
I go through the setup, putting in the key, selecting custom install, etc.  
It tells me to disconnect C:/ to finish installation.  
I disconnect anything that C:/ is plugged into, so now C:/ is just a drive with no wires plugged into it.  
Here's the problem:

(http://imgur.com/qT8FnX1) keeps popping up.  

So to get around that, I held down the power button until it forced shutdown.  
I plug C:/ back in, turn it on, and from the boot menu I chose my hard drive.  
Even while in C:/, it still gives me the setup prompts that I passed succesfully before. As of right now, I am at the screen to enter my license key (which works but I don't know what to do)

Edit: I said how it gives me the setup prompts again. This time it's a bit different, since windows is probably already installed:

Is windows corrupted because I did a force shutdown?
Am I doing something wrong?

A:

You booted from the flashdrive to start the install process. From the perspective of the installer (which is a program running on a "live-in-the-sense-of-live-CD" version of Windows called Windows PE), the C: drive probably is the removable (flash) drive (the message even mentions that it's a removable drive). It is odd that it would still be called C: at that point in the install process, though, because after the first part of the process (where the files are copied over), the system usually reboots and finishes running the installer off the hard disk. At that point, it's perfectly safe to remove the flashdrive, but I wouldn't expect the installer to call it drive C:.
Now, I've installed Windows from a flashdrive many times, and I've never seen that message. I don't use Microsoft's tool, though, I just make the flashdrive bootable using diskpart, list volume, select volume, active, exit and then copying the contents of the install media to the root of the drive. I expect that's all that the tool does, but I'm not sure. I also don't ever need to remove the install flashdrive, but that might be because I only tell the BIOS/EFI to boot off the flashdrive as a one-time thing; it boots from the HD by default.
Have you tried just removing the flashdrive and booting the system (or explicitly booting from the hard disk)? That should start the normal post-install out-of-box-experience, if the installation really did finish. Even if it doesn't work, though, worst case you'll just need to re-install Windows.
The screen you're seeing in the second image is the default partition layout that higher editions of Win8.1 generate when installed on a clean GPT disk. I'm not 100% sure what purpose each partition serves, but one or both recovery partitions are probably related to the "reset"/"refresh" features in Win8+, and the System partition contains the bootloader, etc. and is separate from the main (OS) partition so that you can use BitLocker to encrypt the main partition and still be able to boot. If you like, you can just delete all of those partitions and start again from an empty disk, though Windows will probably just re-create them as-is.

