1. Download cmos.slb and cmos.lib, and store in your hard disk
   (preferably, within C:\Program Files\OrCAD_Demo\Pspice\UserLib).
   Remove the index file cmos.ind if you have an earlier version.
2. From Pspice Schematics menu:
   Choose  Options -> Editor Configuration
   Click on Library Settings 
   Click on Browse, find cmos.slb, and click on Open
   Click on Add*
   Click on OK, OK.
3. From Pspice Schematics menu:
   Choose  Analysis -> Library and Include Files
   Click on Browse, find cmos.lib, and click on Open
   Click on Add Library* 
   Click on OK.