This article will explain
how to fix the permission problem on uploaded files in WordPress running on IIS
7.
I was having the same problem as
you. You upload an image in WordPress and either you get an error or the
image will upload, thumbnails would work but the actual image would not have
read permissions. I’m not an IIS or WordPress expert but after a ton of searching and trying things that didn’t work, this is what worked for me.
If you can’t upload an image at all, it’s probably because you need to give the IUSR account Read/Write/Modify permission on your wp-content folder. This will allow you to upload, and do the WordPress & plugin updates.
