Edward,
A monitor profile is nothing for than a file that defines the characteristics of your monitor, but it is defined in a specific way so the data can be loaded to your video card to help improve the color accuracy of your monitor in applications, such as Photoshop, that can make use of that information. Profiles can become corrupted, in which case you either have to restore the original file from where you first obtained it, or you can create a new profile using monitor calibration software in conjunction with a colorimeter, if applicable.
Given that Photoshop CS3 doesn’t come with Adobe Gamma, the software solution for monitor calibration provided by earlier versions, it seems Adobe now expects Photoshop users to seek out monitor calibration solutions on their own. For a software-only solution which may suffice but is generally less acccurate, you can try an application such as QuickGamma (discussed at <
http://www.normankoren.com)> or Praxisoft’s WiziWYG (free download at <
http://www.versiontracker.com/dyn/moreinfo/win/8064)>. I’m not familiar with QuickGamma and use a colorimeter myself, but I have tried WiziWYG in the past and found it worked pretty well. In any case, the result of using one of these products is that you will have built yourself a new profile specific to your monitor and viewing conditions, which you can then use as your default monitor profile.
Regards,
Daryl