I'm having a problem in transferring photos from Adobe Lightroom 1.4 to my webpage. When I look at the webpage on my Mac, they look great. When I go to a windows machine, the colors on the photos look, dull and the colors washed out. They are all JPG's so I don't know what I'm doing wrong. Please advice and thanks for all your help in advance.
The first thing I would change is your gamma. The default gamma for windows is 2.2, and the default for OSX is 1.8. So, your Mac is set brighter than a Windows machine out of the box. If you are working with photos and designs that require cross platform consistency I would set your Mac to 2.2 to start. Everything will get a bit darker, but will be more consistent.
Now, on to what I think the main problem is....
What colour space are you saving your photos in when you export them from Lightroom?
The only colour aware browser right now is Safari (well, and the latest Firefox). In order for you to have colour consistency across different platforms and browsers you need to save your jpg's in the sRGB colour space.. which is the only colour space browsers like IE recognize.
I would bet you are saving your photos from Lightroom in Adobe RGB or some other colour space, uploading them, and viewing them in Safari.... where they will look fine because Safari is colour aware. But, when you go to Windows, IE or whatever browser you are using doesn't recognize that colour space, and you get the problems you are finding.
Save and reupload them in sRGB and all should be well!