Unfortunately CodeWarrior for MPC5xx V8.7 is not working on Win 7. It is a 32-bit application. Please view the note on its webpage:
http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=CW-MPC5XX
We recommend to use Windows 2000, Windows XP/Vista (32-bit).
These are the official OS supported.
At this time there is no plan for a new version supporting Win 7.
I know a few customers are successfully using CW8.7 on Windows 7, they download the newest 64-Bit-Drivers from P&E for the Multilink-Device, and update some dll's with it.