Unable to delete images from motion-webcam

I keep getting an error when trying to delete a file. It seems as though windows 7 is not authenticating and defaulting me to read only. Has anyone else seen this?
"You need permission to perform this action You require permission from Unix User\root to make changes to this file." :hairpull
"You need permission to perform this action You require permission from Unix User\root to make changes to this file." :hairpull