Do I need to reinstall a Windows Service if I made changes in the code?

I wrote a windows service and installed it. Now I made a few changes to the code and rebuilded the solution.
Should I also reinstall the service?

What does stopping a Windows service do?

When a service is paused, it can maintain internal state, including cached information or possibly even a queue of waiting work items. The service can then be resumed to pick up where it left off. If the service is stopped, internal state is discarded.

How do I install the same Windows service with a different name?

In case you need the same service running on the same host but with different configuration, logically you would use same code just copy the service folder with different configuration and use installutil to install service with a different name.

No, just stop it, replace the files, and restart it.