A little bit of Google searching would of landed you this user guide:
http://support.dell.com/support/edocs/systems/dim2350/k0511bk0.pdf
Next time get off your lazy arse and search and if you don't know how to search then you should not be thinking about fitting a component into your system that you know nothing about, get someone that does know and have them do it!
Also PCI is not the same as PCI Express! A quick PCI vs PCI-E would of told you that.
Another thing, that PC is OLD as in I would not bother in upgrading anything on it OLD.
Sorry to be so blunt but Toms has turned into a NOOB site for the computer illiterate.