Photoshop Colour help -- please please!!

When i do some work in PS, and i go and save it, then when i view it in fax/picture viwer, it is a tad darker and less saturated than what i see in photoshop. Also, when i go to View> proof setup> monitor RGB, the colours desaturate and darken, and thats what i see in fax/picture viewer. So it is a bit like a preview before i save it. This problem is really really frustating. if i dont get ur guys help i am going to commit suiceide. seriosuly. so i think the problem is with my colour settings or w/e. i am not that much of an expert at PS -.- so i rlly need ur help!!

thx in advance =(

You should calibrate your workflow, from input to print. You can use Bridge to unify your colour settings across all of your Adobe products. Use Spyder2 or Huey to calibrate your monitor. Different programs display colour and luminance values differently. It's a frustrating reality. Try using web safe colours on export to web and see if you can duplicate your issues with colour and saturation.