OK...did a little looking and here is what I found. In Windows for ACR 4.6 in CS3, the Camera Raw.8bi file needs to go here:
Program Files\Common Files\Adobe\Plug-Ins\CS3\File Formats
Here is the link to the instructions for installing ACR 4.6.
Installing ACR 5.1 for CS4 (it is not compatible with CS3) is a little different and depends on whether you are using the 64 bit version of CS4:
And those instructions can be found here for ACR 5.1 and CS4.
Now, I wonder how I managed to get an extra copy of it installed in my CS3????
So I removed the extra copy and opened CS3 and a RAW file, and it appears to be working correctly. Interesting.....
Program Files\Common Files\Adobe\Plug-Ins\CS3\File Formats
Here is the link to the instructions for installing ACR 4.6.
Installing ACR 5.1 for CS4 (it is not compatible with CS3) is a little different and depends on whether you are using the 64 bit version of CS4:
To install with Adobe Creative Suite 4 or Photoshop CS4:
Automated installation on Mac or Windows®:
1. Select "Updates..." from the Help menu
2. Follow the on-screen dialogs to download and install the latest available Camera Raw update
Manual installation on Windows®:
1. Exit Photoshop CS4 and Adobe Bridge.
2. Open My Computer.
3. Double-click Local Disk (C:).
4. Navigate to: (Please read directory carefully)
Program Files\Common Files\Adobe\Plug-Ins\CS4\File Formats
5. Move the existing Camera Raw.8bi plug-in to another location (for example, a new folder on your desktop). Ensure you keep this version in case you need to revert back.
6. Copy the Camera Raw plug-in, Camera Raw.8bi, from the download into the same folder as Step 4.
7. Launch Photoshop CS4 or Adobe Bridge.
Manual 64-bit installation on Windows®:
If you are using Photoshop CS4 as a 64-bit application, you can use the Adobe Update Manager to install Camera Raw 5.1. If a manual update of the plug-in is required, please install the Camera Raw plug-in in two locations:
a. The CameraRaw.8bi found at the top level of the zip folder should be placed in the following directory:
Program Files (x86)\Common Files\Adobe\Plug-Ins\CS4\File Formats
b. The CameraRaw.8bi found in the folder labeled 64-bit should be placed in the following directory:
Program Files\Common Files\Adobe\Plug-Ins\CS4\File Formats
And those instructions can be found here for ACR 5.1 and CS4.
Now, I wonder how I managed to get an extra copy of it installed in my CS3????
So I removed the extra copy and opened CS3 and a RAW file, and it appears to be working correctly. Interesting.....