Internet dropping off

[Baandhugh]

i have recently acquired a Macosx.I used to use microsoft XP.When I connected my modem to the Mac and configured my Network options I can only access the web for four or five minutes before it drops off.My ISp is Tiscali,my modem is Sagem 800 and it is connected via a USB.
I would prefer to use a BT Router via an Ethernet connection but the Mac doesn't even acknowledge the BT router is connected.I ahve re-installed the software from the Mac Mini Install Disc.I ahve re-installed the tiscali CD but the problem persists.tiscali say all is ok there end.

[Giaguara]

USB modems will need a driver. That is not provided in Mac OS X system software. Either it will be provided by your ISP or Sagem, ... or if there is no Mac OS X driver for it, you'll be better off with an ethernet modem. Just plug it in and it works.

Why bluetooth? Airport / 802.11 is much faster. Connect your modem to a wireless router and join it over airport (as long as you can still use XP or something else to configure the modem first and then join the wireless router).