How can I change resolution to 600 x 600 px using W.photo gallery

I want to change the image resolution in photo to 600 x 600 px, so can anyone tell me which program should I use for that? At the moment, the same photos open in Windows Photo Gallery? Thanks.

Well, you can use an image editing software to crop the picture to a square and then change the resolution. There is one called Irfanview software. Just search it on the net and download and install it in your pc. It will do the job for you.