If any file can not be deleted, then you can use the program LockHunter, which removes the active connections of other applications to that file, which allow you to change or delete file.
This one for all the people who would like to have a go at designing a nice, clean and stylish looking flyer but don't have much experience with Photoshop.
Nature is everything around us, we are nature and we should be doing everything in our power to preserve it. Now let's learn about nature in Portuguese.
The good folks at the Delft University of Technology came up with a dragonfly-like winged machine that can fly completely autonomously until the batteries allow.