This happened to us when we were installing Exchange UM Role on two of the VM servers. On one server installation was successful & on other it failed. After troubleshooting we found that their is a drive issue with the VM server in question which happened due to old VMware drivers.
This has left us with partial Exchange installation, tried uninstalling it but in vain. UM box got registered in AD/Exchange console & uninstall was failing.
Control Panel shows No exchange server is installed but if We browse thru services ,Exchange services were visible there.
We want to do graceful uninstall so that we can install UM again. Here is what we have done.
- Tried using setup /m:RecoverServer /TargetDir "Path"
This resulted in error, therefore we deleted below registry keys
2. Registry Keys
After that we were able to move ahead:
3. It asked us for the path of Exchnage2010sp3 which we provided & was able to successfully install Exchange.
4. Now when we tried to uninstall, it started throwing below errors of cmdlet not found
5. Here is the last drop that fixed our issues :) --> As we had a successful installation of Same Role on other VM server so we copied the files from it to this new server that was throwing error, skipped the files that already exists.
6. Now We were able to successfully uninstall the Exchange & after that installed UM Role again as per our standard.
Note: This is as per our experience ...