FileNotFoundError: [WinError 2] The system cannot find the file specified:

You cannot use absolute path unless your terminal is in that directory. Hence you can do as following:

import os
def rename(directory):
    os.chdir(directory) # Changing to the directory you specified.
    for name in os.listdir(directory):
        print(name)
        os.rename(name,"0"+name)

As written you're looking for a file named 0.jpg in the working directory. You want to be looking in the directory you pass in.

So instead do:

os.rename(os.path.join(directory,name), 
    os.path.join(directory,'0'+name))