Hi Lotus,
A program that I sometimes use is IrfanView (http://www.irfanview.com). It will allow you to resize your photos, among other things, like crop, save to different formats, add effects/text, etc. The program is primarily a photo viewer and it is FREE. There two downloads for this, the program and the plugins/addons to expand its capabilities.

For a more advanced photo editing program, try the GIMP (http://www.gimp.org/downloads/). Also free.

When I have uploaded photos, I did so from my PC using Firefox and had no problems.

BigDave