From this article you will learn how to turn off OneDrive client on your PC, as well as how to delete the program itself (not all Windows versions offer such a function).
Please note: the fact that you turn off or delete OneDrive will have no influence on the files being stored in the cloud storage. They will still be available via web version of OneDrive.
How to turn off OneDrive in Windows
To turn off the file synchronization with OneDrive storage on your computer you only need to break connection with it. To do this you should find OneDrive icon on the Task bar (it can be hidden – in this case you will need to press the up arrow) and click it with the right mouse button. In the appeared menu you should select “Settings”:

In the appeared window proceed to “Account” tab, click “Unlink this PC” button and confirm your intentions by clicking “Unlink account” button:

Should the need arise you will be able to add your account again.
How to turn off OneDrive client startup
I will demonstrate it, using the example of Windows 10 – you need to open “Task Manager” (by pressing Ctrl+Alt+Del); then, find and turn off “Microsoft OneDrive” in “Startup” tab:

How to delete OneDrive in Windows
Not all Windows versions provide an opportunity to delete OneDrive (in some versions it is an integral part of it). You can try doing it via a standard function of “Programs and features”:

Usually, there are no objective reasons to delete OneDrive client. However, if it fails to operate correctly or just irritates you with its existence in Windows interface – now you know how to deal with it.
If you have any more questions – please ask them in your comments, we’ll be glad to help you!