Just plug the 4s into your computer with iTunes turned off and use the windows photo thing that pops up. Download the lot to my pictures and that's it.
Dropbox all the way. BUT............ how old is your computer? Your display may just not be up to par with later technology. Case in point. I had an old 2007 edition 17" LCD. When I upgraded to a Samsung LED, everything was smoother and more crisp.
When I looked at pics or video I took on my iPad or iPod Touch, everything looked BETTER on my PC!!!