Yeah its a PCI-E 16x slot, not sure if it runs at 2.0 or 1.0 speeds.
Either way its fine for the card you've bought.
When fitting you just unscrew the tabs, take out two - your new card will fill the hole left.
Plug your monitor into the card, the computer should do the rest.
Download the latest AMD drivers here
Vista 64bit <--- This one for 64bit OS
Vista 32bit <--- This one for 32bit OS
Brilliant. Thank you.