[rforte129626]

What sort of hardware must be installed in the desk top? Can a wireless card be used with a USB connection. Or must I use a router?

[NeedKarma]

Are you trying to set up a home network so that you can share files between the computers? Do you want to share an internet connection as well?

[Curlyben]

Now it all depends on what you are trying to do.
If it's a simple case of sharing files, then a simple USB drive would be you best bet.
If, on the other hand you are looking at sharing resources (internet , printers, etc) then your best route would be a router.
Your desktop machine would need a network (NIC) card to connect to the router.
The you can connect your laptop to the same router, either wired or wireless (with a wireless router of course)

The type of router you need depends on your internet connection.
There are different ones for DSL and CABLE connections.
Both are readily available and come with a whole host of inbuilt security.

I would advise against using USB for networking as it can cause unforseen problems. If you want to run wireless on your desktop you can get wireless NIC's.

Hope this helps.

Ps There's a good thread Here that goes into wireless networking.

[rforte129626]

Are you trying to set up a home network so that you can share files between the computers? Do you want to share an internet connection as well?

Yes