Urgent. I use an external USB modem; do I need computer w/internal modem?

get one with an antenna, it boosts the signal so anywhere in your house should work

http://images.google.com/images?hl=en&source=hp&q=...

the one i have will pick up my wireless adapter in my house while i am half mile away in the pasture

and external USB adapters have the extra antenna, internal ones need to be close to the wireless router

modem translates internet signal

if it's already translated, why would u need to do it again?

but i would recommend upgrading that modem to one that connects with ethernet cable as USB ones have been known to have drive issues. Ethernet is faster more reliable an never have an driver issues.

Note: if u want to spread ur internet u need a router, that splits ur translated net signal an handles requests of web pages from multiple machines. It's ok to upgrade ur existing modem to a modem/router (also sometimes called a gateway) as this will allow u to connect to the net, allow u the capability of adding other PC's l8r while also (if u choose to get one with this feature) give u wireless capability, not to mention most routers have inbuilt firewalls that'll give u more protection while online :P

In short if ur lappy offers built in wireless get that instead not modem

an seriously consider upgrading ur existing modem to modem router

No. You'll just connect your external modem to a USB port on the new computer. Done :)

nope, you only need one modem. So get a computer without an internal modem and use your existing USB modem. ;)