Yeah, Photoshop is your best bet in this situation. I doesn't sound like you have it though. But, just in case you do, in Photoshop open you picture..Then go to "Images / Size" and make sure that 'constrain proportions' is checked..and then just change either the height or the width..Then when you save, choose save as..and make the quality of the jpeg about an "8" which is still good quality..That'll make it smaller in both pixels and file size.
Try saving them as .PNG files in Paint..that might help.
Speaking of which..I should take some pics of my car with meh new digital camera.

I'm afraid I wouldn't fit in here, since I have a '92 Pontiac Sunbird SE D:..Civics probably put my car to shame on 1/4 mil times. lates