You can check if samba was installed using several methods:
1. Check the contents of /var/log/packages for the install info file named samba-XXX-i386-Y. (where XXX is a version number, and Y is release number)
2. Use "locate" to locate the "smbd" binary: "locate smbd". If it returns information, then you have it installed.
3. Use find (. . . errr. . . to extreme, but if you want to try it) : "find / -name smbd -print"
Note: you may get a bunch of "permission denied" messages if you are not root, or your current user does not have administrative priviledges to traverse some directories.
And if you have samba binaries locations within your PATH environment variable, you can try using "which smbd" or "whereis smbd".
But if I were you, I would just do (1), and that should be enough . . . I just wanted to let you know all things you could try. . .