Project tries to reinstall, but won't uninstall   

I have had Office 2007 Professional installed for 3 months now. I installed a 
trial version of Project Professional about two months ago. It worked great 
for a while.  I don't know what's changed, but now every time I start an 
Office application, Project tries to install again. I've tried uninstalling, 
reinstalling, and repairing the trial installation of Project, but they all 
get to the same point and stop.  I don't know what else to do.  

I just want to stop this nonsense. Can somebody please help? Details are 
below.

-Doug

The first thing that pops up is a "Configuration Progress" window. It is 
"Configuring Miscrosoft Office Professional 2007". 

After a while, a "Windows Installer" window appears. It claims that "The 
feature you are trying to use is on a network resource that is unavailable. 
Click OK to try again, or enter an alternate path to a folder containing the 
installation package 'PrjProrWW.msi' in the box below". 

I direct this query to a file with that name on my Project 2007 Trial 
installation disc, which I downloaded from the Microsoft web site.

Finally, a window pops up that says "Microsoft Office Project Professional 
2007 encountered an error during setup. Error 25004. Config.Xml not 
specified; a valid config.xml file must be authored when deploying '(null)'. 

Then I can close this window and get back to work. 

What can I do?

-Doug

date: Thu, 2 Oct 2008 11:16:02 -0700   author:   BikerDude