You need to have full permission ("full control") for the drive where the photos reside that you want to upload.
Right-click the drive where the photos reside and select <Properties>, and then the <Security> tab.
In the upper window click on to highlight the user name that represents the account you are currently working from.
In the bottom window it shoud display "Full Control" with a check mark in the column of <Allow>.
If it doesn't display <Full Control> and checkmark for <Allow>, click on <Edit., and again highlight your user name in the upper window and check the box for "Full Control / Allow" in the bottom window.
Do <OK> and <OK>. Then right-click the drive again, proceed to the <Security> tab to check if the new settings are "sticking" (sometimes they don't).