Right click on the pic you want in paint... go to Open With... Paint... Then on paint there is one that says Image at the top... Stretch/Skew... Then to make it smaller make both of them... (it will say 100 in both of them...) make it like 50 and 50. Just make sure you make both numbers the same!!! That way your pic doesnt look silly
But change the number to your preference... If you dont like it just push Edit then Undo, and start again....
I also found a great batch resizing thing, because I have a Sony Cybershot that takes HUGE High Def pics... It is 9MP and I have no need for pics the size of a room, and plus they are Widescreen too. So I got this BATCH RESIZING program for free online. It is called PhotoRazor... It is great... I turned 286 pictures from my camera that were taking up GB's into a bunch of regular size pics, perfect for YT that only take up MB's Now!!! It is great if youre doing a lot of pics... And it did it in like... 2 minutes at the most!