Outlook 2003 still have startup problem

I posted the problem a few weeks ago, and I thought it was fixed after
ActiveSync was installed. Appearntly I was wrong. Here is the updated
information:

After I reinstall Windows XP Pro and Office Professional 2003 (without
re-format the harddisk), I got this error when I start Outlook:

"The application or DLL C:\WINDOWS\system32\Loadperf.dll is not a valid
Widdows image. Please check this against your installation diskette."

Then I installed ActiveSync 3.8. I placed my Dell Axim PocketPC on the
the cradle, and started Outlook 2003. No problem. However, after I
took my PocketPC off from the cradle, reboot the machine, and started
outlook 2003 again, I saw the same problem showing up.

Can anybody give me a hint how to fix this? Thanks!

Bill