Disable Microsoft Office Upload Center
"You can't disable it and if you remove it from start up it still loads up anyway. All you can do is open task manager and end the process for MSOSYNC.EXE, pretty lame I know, but there's no way of disabling it and this info is coming from the office365 forum!"
Not true.
You can disable the Microsoft Office Upload Center easily in the registry- but this is the only way.
Microsoft went out of their way to stop people from doing this in the GUI, and even MSCONFIG won't work.
Here's the registry fix (only tested on Windows 7 + Office 2010... see other answers for more recent versions of Windows/Office):
Locate:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
and delete the OfficeSyncProcess entry that points to the current location of MSOSYNC.EXE.
Microsoft's arrogance on this whole issue is astonishing:
Many people are turning to forums in frustration to turn off this feature.
These people want to disable it, so do these, and these, and even these.
It shouldn't be enabled automatically when you simply run SharePoint/SkyDrive once- and if it is, then it should be possible to turn it off without rolling up your sleeves and hacking the registry.
Poor show, Microsoft. Poor show.
To disable/configure this open up the Task Scheduler and click on the Task Scheduler Library node.
You should see a task here labelled Microsoft Office 15 Sync Maintenance for USERNAME.
Disable the whole trigger (right click and choose disable) or change the Properties of this to amend the trigger that starts the job. For instance, you can delete the trigger that starts on user log on.
Using Microsoft Office 2016 with Windows 10 and the now completely integrated OneDrive application...
Updated for OneDrive Version 2016 (Build 17.3.6517.0809) as of Aug. 2016
Right click on the OneDrive tray icon and choose settings.
Navigate to the Office tab and uncheck "Use Office to sync office files"
- Reboot computer and Office Upload Center will no longer load at start-up.