Assuming you mean a TIA/EIA 568A to B (or B to A), these carry digital data that cannot be used by an audio receiver.
If you want to transfer audio, the laptop probably has a stereo 3.5 mm socket for each of its audio in and out, so you'll need a lead (or leads) with 3.5 mm plug(s) at one end, and the plugs your audo gear uses at the other - most likely RCA connectors.
If both have a network connection you can use a crossover network cable.
Assuming that by CPU you are referring to a separate desktop machine, you can use a crossover ethernet cable to connect them directly
A crossover cable.
If you are using a crossover cable, simply assign static IP's to each machine (192.168.0.2 and 192.168.0.3). If using regular network cable, you will need to use a network switch or hub to connect them together, still using the static IP's for each machine.
There are a number of ways to connect a laptop to a receiver, and the type of receiver will determine what methods can be applied to make the connection. A more specific question will yield a more specific answer.
thru HDMI
Just connect the Ethernet cable (RJ-45 crossover) to the laptop .Then you will get the connection.
Either connect via a wireless network, connect through a 3G network or connect your laptop with an ethernet cable.
Buy an RJ45 crossover cable for less than 5$, connect the laptops and you are all set. If your laptops are equipped with modern gigabit network cards a straight-through ethernet cable should work as well.
when we connect one laptop in own network then internet dont working what is the problem
First you need to see if you have a built in wireless receiver. Go to the start menu and find printers and devices. if you have a built in receiver, go to network settings and you should find a connect option. If you do not have a built in receiver you will have to buy one and follow the same steps.
network hub