I had similar problem, where nothing helped with this problem (clearing cache, clean boot, administrator priviledges, UAC, firewall settings), but ultimately I managed to solve it at least for me. The problem was with windows itself, in my case windows 7. My windows update had become "stuck" in a way, which seems to be not so rare problem. Solving the update problem allowed me to install critical and optional updates, which then solved all problems with origin. This is what I did:
1. Go to your windows update and try to update. In my case, I got the error "windows update cannot currently check for updates because the service is not running. you may need to restart you computer"
2. There are several ways to solve this, but for me what worked was to delete windows update temporary storage folder. This causes you to lose your update history, but it allows you to update your windows again. Apparently Intel Rapid Storage Technology Driver (Intel RST) can also be behind the problem and installing latest drivers may solve the problem. Installing KB3102810 Standalone Update has also been reported to solve the update problem. More info can be found from: https://www.wintips.org/windows-update-cannot-check-for-updates-windows-8-7-or-vista-solved/ , but I'll write here what I did according to that link.
3. To delete the update temporary storage, we first need to take windows update off for a while. Hit "Windows key + R" and type in the command box services.msc and hit enter. Search for Windows Update Service from the list, right click on it and select stop.
4. Go to C:\windows\SoftwareDistribution and delete the contents.
5. Back at the Services list right click on Windows Update Service and select start.
6. Try to update windows again, now it takes sometime as it establishes the current update level. For me, it offered ~4 critical updates and about 40 optional ones, of which I installed everything.
7. I uninstalled Origin restarted computer and installed it again.
8. All problems vanished and I could once again download and update games!
Apparently newer origin versions rely on certain windows updates, and this might explain why for some people origin just suddenly stops working sometimes: windows updates get stuck. Windows doesn't really tell about this, unless you yourself go and check it, so that's why I guess it goes unnoticed.
I hope this might help some of you, who are stuck with this annoying problem with Origin not downloading/updating games.
