The first thing to check is to make sure you do not enter in the dashes, also, do not copy/paste the number into the field.  This will cause errors.
If the above steps do not work and the error message still shows, this can only mean the product you are trying to activate does not match [...]

This error can occur on Windows XP, Vista, and 7. Please make sure the latest version of Microsoft.net framework 3.5 installed along with Visual Studio 2008 C ++.
Please click here to download and install Microsoft.net Framework 3.5
Please click here to download and install Visual Studio 2008
These are “helper” files needed from Windows (XP, Vista, and [...]

Please make sure the latest version of Microsoft.net framework 3.5 installed along with Visual Studio 2008.
Please click here to download and install Microsoft.net Framework 3.5
Please click here to download and install Visual Studio 2008
These are “helper” files needed from Windows (XP, Vista, and 7) for our programs to work properly. In most cases, the Microsoft [...]

Here is the error window you will see:

Please close all of your applications currently open (Photoshop, etc). To remove this error message, please remove the following two files which are parts to the onOne Library:

onOne Library.dll
onOne Library.acel.8bx

These two files help create the onOne menu. These files are in the following location:
Windows: \Program Files\Adobe\Adobe Photoshop CS4\Plug-Ins

Please [...]

PLEASE READ THROUGH THIS ENTIRE ARTICLE BEFORE UPDATING
In most cases updating video card drivers will fix this issue. This will not be the case for all video cards. These products require the video card supports OpenGL 2.0 or greater with a recommend 256mb of memory. If the video card does support OpenGL 2.0, please make sure the video card drivers [...]

Please download the OpenGL Doctor application by clicking here. Once you run this application, it will show which version of OpenGL is supported. Please see the example image below (OpenGL support is shown in the red box).

If you do not find your product listed below please contact customer service.
NOTE: Please DO NOT use the below download links if you are interested in a trial version of the products. Please click here to download a trial version.

Plug-in Suite 5
Macintosh – Current version 5.1.1
Windows – Current version 5.1.1
Plug-in Suite 4
Macintosh – Current [...]

The following products will support the 64-bit version of Photoshop CS4 (Vista and 7 only).

Plug-in Suite 5
Genuine Fractals 6.0.4 (Standard and Professional Edition)
PhotoTools 2.5 (Standard and Professional Edition)
PhotoFrame 4.5 (Standard and Professional Edition)
FocalPoint 2
PhotoTune 3

If you have older versions of the above plug-ins and a 64-bit computer and version of Windows you can still install and run the 32-bit and [...]