Edit: I just saw your new post; try creating a new folder on D and directing Origin to install there. If that doesn't work, try the steps below.
@PinkTweedy Where a program is downloaded has no impact on where it gets installed, or at least it shouldn't. I have downloads still set to C, but when I went to install Origin, my system asked where I wanted it, and I chose D. This was a clean install of Windows though.
If you uninstall "the hard way" and reinstall, I would think you'd have the option to choose the install location. If not though, try uninstalling Origin with Revo Uninstaller (the free version works fine, either regular or portable). First, clear Origin's cache:
https://help.ea.com/en-us/help/faq/clear-cache-to-fix-problems-with-your-games/
Then use Revo to remove all traces of Origin, except for the Origin Games folder. Here's how:
- Quit Origin, then right-click on the Task Bar and open the Task Manager. Scroll through looking for Origin entries. If you find any, click on them and End Task.
- Download Revo Uninstaller from here (again, the free versions are fine).
- Install Revo, open it, and uninstall Origin. When it's finished, Revo will ask you which cleaning method you want to use. Select "Moderate" and then Browse.
- If Revo finds any remaining registry entries, select all, delete, and click Next.
- Revo will display "Remaining Data and Folders. Select all of them except for any "Origin Games" folder you see on D. (I don't know if you have any other Origin games installed, but there's no need to remove the ones in the correct location.) Delete the rest.
- Restart your computer.
Next, download and install Origin—the regular version, not the beta. Here's the direct download link:
http://download.dm.origin.com/origin/live/OriginSetup.exe
Be sure to run both the installer and Origin itself as an admin: right-click on each and select "Run as Administrator." Again, you should be asked where you want it installed, regardless of where the download is.
If you still don't have a choice of where to install it, do another clean uninstall, create a new admin user account on your PC, and install Origin into that, using the full installer and running it as an admin. You can delete the new user account when you're done; this is just to bypass any user-specific settings on your main account that might be getting in the way.