Recently, I was working on an interesting case where we were not able to configure Biztalk Rules Engine in Biztalk Server 2006. All the other components got configured sucesfully but BRE was failing with error "Rule Engine Update Service is not a valid Win32 application" in the event logs. Now, it was getting pretty urgent for customer.
Now, the thing was looking simple with KB 812486 but as the configuration wizard fails, it deletes the
RuleEngineUpdateService and the associated registry as well. So we do not get a chance to modify the image path in the registry.
Next thing we looked for a folder with name 'Program' under the root drive (i.e. C:\) as per KB 812486 and could
not find any such folder . Now, it was after sometime only, that it strike our mind that it could be a file with the name 'Program' and that was it. After removing this file, BRE got configured succesfully.
The question here is how did this file 'Program' got created under root drive. We can't answer this. 🙂
I hope it helps! (atleast to few) Rest, we are always here 🙂