Simply put, when I go through the uninstall option for the game I'm hit with the following:
Runtime Error (at 226:759): SWbemObjectSet: The RPC server is unavailable.

Checking online about 226 runtime errors, the only suggestion I could find related to deleting the program through the control panel add/ remove programs option, but that route throws up the same error. Can anyone help? Thanks.

Try reinstalling the game and then uninstall.

Some registry entries might be broken or something else. I'd just reinstall the game over your current installation and then try to uninstall it.

EDIT: Hehe, got ninja'd by triock

I tried reinstalling, but it doesn't seem to have worked. Is there anything else I can do?

You can just delete the directory.
Planescape doesn't use the registry so the only registry entry for it is the installation path to torment.exe

You can leave that & it won't cause any issues, or you could delete it with regedit.

Try Revo Uninstaller - http://www.revouninstaller.com/revo_uninstaller_free_download.html

I'll try those suggestions out once I get the chance. Thanks, everyone.