Dan,
If you tried installing a version of ACR later than 3.7, it WON'T WORK. Download v3.7 from here:
http://www.adobe.com/support/downloa...jsp?ftpID=3588
then follow the instructions I've pasted below.
After downloading a ".zip" file, use the operating system or a utility such as WinZip or PKZIP to access the file's contents.
To install with Adobe Creative Suite 2 or Photoshop CS2:
1. Exit Photoshop CS2.
2. Open My Computer.
3. Double-click Local Disk (C: ).
4. Navigate to: (Please read directory carefully)
Program Files\Common Files\Adobe\Plug-Ins\CS2\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 CS2 or Adobe Bridge.
NOTE: If generic camera thumbnails appear in Adobe Bridge, follow the these steps:
1. Check to make sure the plug-in was installed in the correct directory in step 4 above.
2. Start Bridge.
3. Choose Tools > Cache > Purge Central Cache.
Important: Purging the Central Cache deletes cached thumbnail information for all folders. It also deletes labels, ratings, and rotation settings for read-only files (for example, files on a CD or locked files) or file formats that don't have XMP support.