Thank you guys!
Actually, I edit pictures for websites not for printing. Does that make a difference?
So you're editing images for web sites that aren't your's? You're doing the editing to make some income?
What type of display do you have - Twisted Nematic (TN), In-Plane Switching (IPS), Patterned Vertical Alignment (PVA)?
What color bit depth is the display capable of?
If your display is only a 6-bit display calibrating it isn't going to help much because the range of colors it can show is so lmited.
As john.margetts points out most personal computer users and non-photography web site owners never calibrate their display(s), let alone calibrate their display on a regular basis, which is what image editing pros do.
But image editing pros generally have higher end displays that are at least 10 bit displays costing from a thousand to several thousand dollars. some image editing pros use 16-bit displays that are in the $10,000(s) price range.