Assuming you have an ASDL broadband, all you need is a router, some cables (usually in the router pack) and connections on the PCs
Some PCs have an ethernet 10/100 connection already on the motherboard, with others you will have to buy a PCI card, or something to connect to the router.
If all you need to do is share an internet conn (rather than share a printer or files between the computers) then it's pretty straight forward.
Please advise make and model of the laptop and PC for more specific advice.
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