Go to Windows Defender, and under "real-time protection", push the slider to the left, to temporarily turn it off. Note that the program will be turned on again upon the next system start. In my screenshot, the options under Windows Defender are greyed out because I also have a "main" anti-virus system (avast Internet Security). It seems that if Windows detects a third-party anti-virus system, then Windows Defender will be turned off automatically. That means for you: if Windows Defender is your sole security program, read the following to configure the exclusions, or if you have a third-party anti-virus, then you may skip this part.