Unable to delete video file after dropping it in my Uploads folder

I have set up my iCloud Control Panel on my Windows 7 PC and have inadvertently added an *.MP4 video file in the "Uploads" folder instead of a photo. When I try to delete it, it states: "The action can't be completed because the file is open in ApplePhotoStreams.exe." This file is nowhere to be found and I cannot delete it from my Uploads folder.

I tried uninstalling and reinstalling iCloud, to no avail. Please advise what I can do to delete this file. Streaming of photos both upload and download work very well. Appreciate any assistance or advice.