Consider before removing the Exchange 2010 manually:
A: Is the server the OAB Generation Server?
B: Is it the host for any connectors or subscriptions to Edge servers?
C: Are there any public folders that need to be re-homed to other servers?
D: System state backup did not completed successfully today?
If any of these are YES than you should take care of it before you start uninstalling the server.
By following the below steps you can remove the exchange server manually from the computer/server.
1: Take the flat file copy of database.EDB file in case you want to mount the database on some other server.
2: Stop and disable all the below exchange services. Click on Start…>Click on Run…>Type Services.msc
Note: In your case you might see lots of other services depending on the number of exchange server roles you have installed.
3: Remove all exchange registry from the server from the below location
Note: Take registry backup before deleting it. It’s always a best practice.
Note: In your case you might see more or less registry keys depends on number of Exchange Server Roles you have installed on the server.
4: Open windows explorer and go to the location C:Program FilesMicrosoftExchangeServerV14bin, delete the bin folder. Bin folder contains all the binary files of exchange server.
If you are getting Access error message or File is locked/used by other program, than you rename ExchangeServerfolder to ExchangeServer_OLD. After renaming the folder delete the ExchangeServer_OLD folder.
5: Go to Adsiedit.msc…>Configuration…>Services…>Microsoft Exchange…> Administrative Groups…>ExchangeAdministrativeGroup…>Servers…> here you will find all the exchange 2010 server you have in your environment. Delete the server you are uninstalling.
Note: Follow the above step as mentioned, if you delete something else other than mentioned in the article you will/might break the exchange environment.
6: Restart the exchange server and go to Control Panel…>Programs and Features…>Make sure you don’t have Exchange Server Object listed here, but sometime you will see the Exchange Server 2010 listed but the size of the server will be in MB’s. I call is shadow of Exchange Server
Remove the server from Programs and Features, it will take less than minute to remove the exchange object from Programs and Features.You have successfully uninstalled/removed exchange server 2010 manually