i've already install last build of servicedesk plus in standard driver C:\. 

Now i would like to change the driver (from C: to G:, for example) but when i try to copy the installation folder (ManageEngine, I also try to copy the subfolders Servicedesk, even every single file) it gaves me an error: "unable to copy file". I've follow this steps:

How do I move ServiceDesk Plus installation to a different drive on the same server?

Follow the instructions below to move ServiceDesk Plus installation to a different drive on the same server.
Step 1: Stop ManageEngine ServiceDesk Plus service.
Step 2: De-Register Service: C:\ManageEngine\ServiceDesk\bin> sd_service.bat -r ..\server\default\conf\wrapper.conf
Step 3: Copy installation folder [ManageEngine\Servicedesk] to another drive say D:
Step 4: Re-Register service: D:\ManageEngine\ServiceDesk\bin> sd_service.bat -i ..\server\default\conf\wrapper.conf
Step 5: Start the service.
NOTE:Make sure you have taken the backup first using backUpData.bat in ManageEngine\Service Desk\bin before you perform the procedure.

I have an error during step 3. 

What can I do?!

thanks