One of our customers has an issue with a webapp.
The eventlog shows:

Code:
The Module DLL C:\Program Files (x86)\DataFlex 19.1\Bin64\WasHttpMod.dll failed to load.  The data is the error.
There is no data.

So I want to re-install webapp server. I need want to put the files in another location anyway., but I can't.
When I try to uninstall Dataflex webapp server, it tells me:

Click image for larger version. 

Name:	webapp.jpg 
Views:	22 
Size:	36.8 KB 
ID:	16937

I have administrator rights.

When I try to re-install webapp server, I can't because it tells me I need to uninstall webapp server first. But I can't.

So I try to fool the installer by renaming all paths and registry settings, but then the installer pops up with an error:

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Name:	webapp2.jpg 
Views:	22 
Size:	88.0 KB 
ID:	16938

So I'm stuck here.

Any suggestions?