Deleting Screenshots

[eXtr3m3]

Well, to save space and a hassle, I usually delete screenshots after I no longer need them. So I quit CS:S to go play Garry's Mod and the Steam screenshot uploader came up, so I went to delete the screenshot from there. Later on, I go to view my screenshots folder. I went onto it and it shows that the screenshot I deleted is still there. So I try to delete it and it says I need permission from an administrator. The only problem is, I'm the only administrator on this laptop.