Here is a tech fact I found.

Technical Resource Library and Acrobat Reader 4.0

Adobe Acrobat Reader 4.0 can be used to view the files on the Technical Resource Library CD. However, the library’s installation procedure does not automatically locate the Reader 4.0 PLUG_INS directory. To use the library with Acrobat Reader 4.0, install the CD as follows.
1. Make certain Acrobat Reader 4.0 is not running.
2. Insert the Technical Resource Library CD into your CD ROM drive.
3. From your desktop, click the Start button, and then click Run.
4. When the Run dialog box appears, type
(Your CD-ROM drive letter):\setup, for example, d:\setup.
5. Click OK. The installation program begins.
6. Follow the instructions on each screen until you get to the Choose Destination Location dialog box.

Good Luck
Walt