If you are trying to use the PCMCIA card with the existing modem, you are not going to see any luck with the wireless because of the simple fact that the modem that you have, I dont' think it's got wireless. So my friends, as an All in one solution to your problem, I would advise you to go for a wireless router.
check my post in the thread *www.thinkdigit.com/forum/showthread.php?t=29143&page=99 for more on wireless routers.
You dont' need to install the modem if the computer has a LAN port/card. But if he's got USB, you can download the latest drivers for the modem from
*www.huawei.com. Copy that onto a CD/pen drive from somewhere else and then take it to your friends place and install it like any other driver.
However, if you are going to use the LAN card, then first reset the modem with the help of the reset button at the back of it. (don't do this if you dont' remeber the username/password). Then just plug the modem up with the LAN cable and go into the LAN TCP/IP properties and set this address manually:
I.P: 192.168.1.2
Subnet: 255.255.255.0
Default Gateway: 192.168.1.1
Once this is done, open IE and go to the address 192.168.1.1 and enter the username: admin and password: password.
Then go in and enable the DHCP server on the modem and put in the dataone username and password and put your TCP/IP settings on the computer back to automatic. You should be able to browse absolutely fine now.