Restore-Spsite -Force not working

I'm quite new to SP and while trying to restore a site collection (same version) to a new area I get the another site collection already exists, choose a new url or use -Force error. Which would be fine if I wasn't already using -Force.

I assume that I am forgetting something/leaving something out when I run the cmdlt.

What I enter is as follows:

Restore-Spsite -Identity http:// -Path C:\backup.bak -Force

The above is being run in the sharepoint management shell.