If your on a laptop or desktop...just go to your start menu and type in > paint ....... on most you will be able to then click on paint to open the paint program. I re-size all my Images that way. Go to youtube and search ( Microsoft paint tutorial resize an image) and away you go. Hope this helps some. I do realize that perhaps most know this already! You can also right click to access paint in most cases.

 

It is something that the forum software is capable of doing. I do use free software to edit/resize my own pictures though. GIMP - The GNU Image Manipulation Program GIMP is a photo editing software similar to Photoshop.....though it has a pretty sharp learning curve and would be a bit of overkill if you are just wanting to resize images. It's not something that you just upload a picture and it spits out image size/dimensions you want.

I am pretty sure that Windows has a program pre-installed that is capable of resizing images fairly easily. There are also several options I found with a quick Google search. However, I cannot vouch for these programs and I won't link any program download links that I have no personally used because of the virus risks with Windows.