If I recall correctly, GP3-2k will never install from the CD for some people (including myself), so:
1.Copy all of the files on the GP3-2k CD into an empty new folder on your hard-drive.
2.Copy all of the files of the "GP3-2k Install Fix" into the same folder on your hard-drive.
3.Run the installer file in the new folder on your hard-drive that now has all of the above files in it.
4.GP3-2k should now install into the proper directory on your hard-drive without requiring that a GP3 or GP3-2k CD be in a CD-drive.
5.Try out the newly installed GP3-2k and see if it runs allright.
6.If it does, then delete the folder that you created with all of the GP3-2k CD and GP3-2k Install Fix files in it that you used to install GP3-2k.
7.If GP3-2k does not run, then repeat steps 1 through 6 above.
8.If GP3-2k still does not run, then I am afraid that I cannot help you any further.