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Not in any way as easy as iChat's "Screen Sharing" option, but it is possible. VNC would probably be the best option both ways, but it takes some doing to configure (especially if you're both behind NAT routers).

EDIT: VNC, not VLC. Brain fart.
 
Not in any way as easy as iChat's "Screen Sharing" option, but it is possible. VNC would probably be the best option both ways, but it takes some doing to configure (especially if you're both behind NAT routers).

EDIT: VNC, not VLC. Brain fart.

We're both in the same network.
Do I just install a VNC client on the Vista PC and then use the 'share screen' button in the Finder to start the screen sharing app?
 
Install the VNC Client, go to Finder > Go > Connect To Server
and type:

vnc://VistaIPAddress
 
We're both in the same network.
Do I just install a VNC client on the Vista PC and then use the 'share screen' button in the Finder to start the screen sharing app?

Are you trying to control the Mac's screen with the Vista PC? (Then the VNC client on Vista is what you want; Don't forget to turn on "Screen Sharing" under System Prefs -> Sharing on your Mac.)

If you're looking to control the Vista machine, install TightVNC (the full service) and you can control the PC as well as let the PC control the mac. The quickest way I've found to launch VNC control is (from the Finder) hit Cmd-K, then type "vnc://1.2.3.4" where 1.2.3.4 is the IP address of the target host.

Install the VNC Client, go to Finder > Go > Connect To Server
and type:

vnc://VistaIPAddress

It should be noted that the OP has to install the TightVNC service, not just the client, to connect to Vista.

The client is only a viewer. The service is the server.
 
It should be noted that the OP has to install the TightVNC service, not just the client, to connect to Vista.

The client is only a viewer. The service is the server.

Right, I'd thought that was pretty obvious.
 
UPDATE

We bought a 5-user license of Remote Desktop for the other Macs at home.

Now I want to control the Vista PC with it as well.
I got the Vista IP address. I installed TightVNC on the PC. The service is launched. I got the admin username and password. I can remotely access the files on the PC in the Finder.
The status of the Vista PC in Remote Desktop says 'VNC available'

And still it's giving me this error message: Authentication failed to 'Vista PC'

Anyone know what might be causing the problem?
 
Alright I got it to work. A bit strange though.
It wouldn't work when I used the admin login, but it DID work when I used a random other login (not even a user on the computer)
 
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