I've just bought an ethernet modem for my ADSL internet connection.
Now i want to use the same internet in my laptop but i dont know how
to share the internet connection because the ethernet port on my PC
its used by the modem so the pc cant be connected in a network. Anyone
got solution for this ? Is there any way 2 share the internet if I add
a new netwrork card in my PC or there are other ways?

If you prefer to go down the cheaper route of getting yourself a new
network card and running proxy software on your PC, I'd suggest using
the excellent (and free!) Proxy+

I'm not affiliated with the company in any way and I've used it myself
for over a year now without any problems - it's really simple to set
up as well.

Thats what i was looking for :) but i need adition information. Please
provide the URL of where i can find Proxy+, I searched in google and
there are many products with that name its too confusing.
Other softwares are wellcomed too ex. WinRoute its good but I dont
know why when i install it on my PC i can connect to the internet but
the net traffic its not going on :( i cant open websites.

The homepage for the software is the first one that pops up in google
- www.proxyplus.cz, most of the others just point to mirrors where you
can download identical copies of the software.

I would suggest, in the case of the proxy software you're already
using, that you make sure you've set Internet Explorer within the
tools -> internet options menu, under the connections tab, then lan
settings, that you tick 'use a proxy server for your LAN' and input
the address of the machine connected to your modem and running the
software, as well as the port number that the software is configured
to use. Within Proxy+ this is typically port 4480.

i would just install another network card in your computer and use
microsoft internet connection sharing which is built into most
versions of windows.  i wouldnt use that 3rd party stuff.  usually if
3rd party software is free it is full of adware and spyware.

In direct contrast to cp0791's comments, I *strongly* recommend not
using the built in ICS feature that windows has. It's got to be the
poorest and most pathetic excuse for routing software I've ever had
the mispleasure of using - and this is echoed on a number of forums
across the net. I would definitely recommend a hardware solution, or
at least a third party software solution - of which I can guarantee
Proxy+ is entirely free and has no adware/spyware at all.