Thanks for your response. Your example illustrates what I used to have on my computer when I had CS3 with my calibrated monitor. But I am still having issues with colour differences between CS4 and windows picture and Fax viewer. I thought I'd post up an example two examples here. The strange thing is when i set my default monitor profile to sRGB the colour differences between cs4 and windows picture and fax viewer dissapear. Digital dogs says this is not a fix and I know this. But being as cs4 and windows picture and fax viewer are both colour managed why is it that the colours are different when im using a dedicated monitor profile??
If you have gone to the trouble of profiling your monitor, you definitely don't want to set the windows default monitor profile to sRGB, even though it does remove the differences you noted. Windows and Fax Viewer is color managed to some extent as I showed by opening files in various color spaces--they look reasonably good on the monitor. This shows that Windows and Fax Viewer does read the profile attached to an image and displays it accordingly. Of course, proper color management requires that both the source and destination be displayed using profiles. Photoshop definitely uses the monitor profile when displaying images, but perhaps the Windows Viewer simply assumes output to sRGB. This would explain the behavior you noted.
Why do you want to use Windows Viewer in the first place? For JPEGs TIFFs, etc one can set the default software that opens the image. If you don't want to open Photoshop merely to view a JPEG, why don't you try setting the default to another viewer such as Irfanview? It is freeware, loads fast and has many options. Also, do you see these differences with other color managed programs such as Firefox?